Answer:
Independent: whether or not there was fertilizer in water
Dependent: height of plants
Explanation:
In an experiment, there is an independent and a dependent variable. The independent variable is what is changed in the experiment. The dependent variable is what is measured.
In this experiment, 10 tomato plants are given fertilizer in the water, while 10 other tomato plants are given regular water. Everything else is kept constant, and the heights are measured at the end of the week.
The independent variable is what is being changed. In this experiment, the only thing being manipulated is the fertilizer. One group of the plants is given fertilizer, while the other is not. Therefore, the independent variable is whether or not there was fertilizer in the water.
The dependent variable is what is being measured. In this experiment, the thing that is being measured is the height of the plants. Therefore, the dependent variable is the height of the plants.
How does fuel burn in a diesel vehicle?
Answer:
it burns through oxygen gas.... through the process known as combustion.... combustion is the process of burning materials in the presence of Air
The graph below shows how the temperature and volume of a gas vary when the number of moles and the pressure of the gas are held constant. How can the volume of the gas be increased if the pressure is constant?
Answer:
Option C. By increasing the temperature
Explanation:
From the graphical illustration above, we see clearly that the volume and temperature of the gas are directly proportional. This implies that as the temperature increases, the volume will also increase and as the temperature decreases, the volume will also decrease. This can further be explained by using the ideal gas equation as shown below:
PV = nRT
P is the pressure.
V is the volume.
n is the number of mole.
R is the gas constant.
T is the temperature.
PV = nRT
Divide both side by P
V = nRT/P
Since n and P are constant, the equation above becomes:
V & T
V = KT
K is the constant.
The above equation i.e V = KT implies that:
As T increases, V will also increase and as T decreases, V will also decrease.
Considering the question given above,
The volume of the gas can be increased if the temperature is increased.
rainwater is slightly acidic.why?
Answer:
Rainwater is slightly acidic because...Water reacts with carbon dioxide to form carbonic acid. Due to high carbon dioxide emission in oceans, it explains why sea waters are acidic. Carbonic acid then breaks down into hydrogen ions and hydro carbonates ions. The hydrogen ion raises the water pH and, thus, causes the rainwater to be slightly acidic.
Answer:
Explanation:
rainfall is slightly acidic because of the presence of dissolved carbonic acid. ... The gases of sulfur oxides and nitrogen oxides are chemically converted into sulfuric and nitric acids.
CHEM HELP PLEASE
a reaction that has been calculated to produce 346 g of CH3OH actually produced 312 g of CH3OH. what is it's percent yield?
Answer:
90.2%
Explanation:
% yield = actual yield/ theoretical yield * 100%
% yield = (312/346)*100% = 90.2%
Can a compound have more than one carbon-carbon double bond in it?
Answer:
yes, a compound can have more than one carbon-carbon double bond
How are the particles in solid ice similar to the particles in liquid water, and water vapor? How are they different?
Matter are anything that is made up of atoms. The similarity among solid ice, liquid water and water vapor is the water molecule and dissimilarities is the difference in kinetic energy.
What is matter?Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.
The similarity in the in the particles of solid ice, liquid water and water vapor is that each of these have same type of molecules that is water molecules. The dissimilarities in the in the particles of solid ice, liquid water and water vapor is that particles of of each of these have different kinetic energy.
Therefore, similarity among solid ice, liquid water and water vapor is the water molecule and disimilarity is the difference in kinetic eneergy.
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Give four differences between rusting and burning
Answer:
burning is a rapid process, rustig is a slow process. burning releases light during the process,rusting does not. burning can speed up with addition of more external conditions, rusting cannot be sped up greately by addition of external materials. burning results in release of large amts of heat, rusting very little amt of heat
Hope helped
plesse give a thank
and most brainlest
-Rust happens when something is unpolished and is old. Burning has been modified by heat.
-Burning is a chemical change. Rust is a physical change.
-Burning something cannot be fixed back to its natural form, while when something is rusted it can possibly be re-used and fixed.
-The texture of something burnt is usually fragile and brittle while rust makes (metal for example) gritty.
-Rust usually forms solely on metals while almost anything can be burned.
note: you asked for 4 answers but i gave you 5 in case you didnt like any of them. Hope this helps!
The table below shows the similarity of Methane and water in molecular mass. They are also similar in both size and shape. Why does Methane exist in the gas state with a very low boiling point?
Answer:
Explanation:
In case of Water there are strong hydrogen boding excist as result shows high boiling point, wher as in case of methane the there is no hydrogen bond and excist weak vanderwall attraction between the molcuels so the lower boiling point.
A balloon has a volume of 10,500 liters, and the temperature is 15°C. If the temperature were -25°C, what would the volume of the balloon be?
12,194 L
9,042 L
12,194 L is the answer!
Explanation:
Water has the maximum density at the temperature of 4°Celsius. So, it expands at temperatures higher or lower than 4°C, knowing that at the temperature of -25°C the water can't have a lower volume than the one at 15°C.
Answer:
12, 194 L
That's your answer!!!
The pictures to the right, show two different models
of the atom. Type in the letter of your answer.
Which model best represents Dalton's atomic
theory?
Answer:
The pictures to the right, show two different models of the atom. Type in the letter of your answer.
Which model best represents Dalton’s atomic theory?
B
Which model best represents the modifications to the theory that Thomson’s results made necessary?
A
The model that represents Dalton's atomic model is the B model.
Dalton's Atomic TheoryDalton was a scientist who described how the atom is characterized, stating that the atom would be a massive and indestructible sphere, that is, it was not divided into subparticles (electrons, protons and neutrons).
Thus, model B is the most suitable according to Dalton's statements.
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boron has two naturally occurring isotopes .there are 10 b(20%)and 11b(80%).what is the average atomic mass of boron
Answer:
Explanation:
Average Atomic mass of any element =[ ∑ Abundance* mass of element] /100
= 10*20 +11*80 /100
= .........
Hope this helps you
According to solubility rules, which of the following compounds is soluble in water?
A. Na Coz
B. BaSO4
O C. Ca(NO3)2
D. K3PO4
Answer:
Na2CO3
Explanation:
Na2CO3 is a compound soluble in water. So the correct option is A.
What are solubility rules?
The common ionic solids' solubility laws are as follows. When two rules seem to conflict with one another, the prior rule is used.
Group I element salts (Li+, Na+, K+, Cs+, and Rb+) are soluble. The few exceptions to this rule are rare. Ammonium ion (NH4+) salts are also soluble in water.Nitrate ion (NO3-) salts are often soluble.In general, salts containing Cl, Br, or I are soluble. Ag+, Pb2+, and (Hg2)2+ halide salts are significant exceptions to this norm. PbBr2, Hg2Cl2, and AgCl are hence insoluble.Silver salts are often insoluble. Most silver salts are insoluble, with the exception of AgNO3 and Ag(C2H3O2).Sulfate salts are often soluble. This rule has some notable exceptions, such as CaSO4, BaSO4, PbSO4, Ag2SO4, and SrSO4.The majority of hydroxide salts are hardly soluble. Group I element hydrate salts are soluble. Group II elements (Ca, Sr, and Ba) have soluble hydrate salts. Transition metal and Al3+ hydrate salts are insoluble. Fe(OH), Al(OH), and Co(OH)2 are so insoluble.The majority of transition metal sulfides, such as CdS, FeS, ZnS, and Ag2S, are very insoluble. Sulfides of lead, antimony, bismuth, and arsenic are also insoluble.Many times, carbonates are insoluble. Group II carbonates, including CaCO3, SrCO3, and BaCO3, as well as FeCO3 and PbCO3, are insoluble.Most of the time, chromates are insoluble. PbCrO4 and BaCrO4 are examples.Many phosphates, like Ca3(PO4)2 and Ag3PO4, are insoluble.Many fluorides, including BaF2, MgF2, and PbF2, are insoluble.
Therefore, the correct option is A
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) What is the definition of an enzyme? A.Enzymes are carbohydrate molecules that act as catalysts to speed up chemical reactions in living things. B.Enzymes are polymer molecules that act as catalysts to slow down chemical reactions in living things. C.Enzymes are protein molecules that act as catalysts to speed up chemical reactions in living things. D.Enzymes are fat molecules that act as catalysts to speed up chemical reactions in living things. E.Enzymes are protein molecules that act as catalysts to slow down chemical reactions in living things.
Answer:
option c
enzymes are protein molecules that act as catalysts to speed up bio chemical reactions
The oxide of element X is reduced by heating with carbon.Element X does not react with cold water, steam or dilute hydrochloric acid.What is X?
The question is incomplete, the complete question is;
The oxide of element X is reduced by heating with carbon.
Element X does not react with cold water, steam or dilute hydrochloric acid.
What is X?
A copper
B iron
C magnesium
D zinc
Answer:
Copper
Explanation:
Copper is below hydrogen in the activity series of metals. Remember that the activity series of metals is an arrangement of metals in order of decreasing reactivity from most reactive to least reactive. The metals at the head of the series are highly reactive, metals at the middle of the series are moderately reactive while metals below hydrogen in the series are least reactive.
Copper being below hydrogen in the series cannot displace it from water (cold or steam) or from dilute acid solutions. Copper can be reduced by heating it with carbon (thermal reduction).
If two identical atoms are bonded together, what kind of molecule is formed?
A. A bent, nonpolar molecule
B. A linear, polar molecule
C. A linear, nonpolar molecule
D. A linear, ionic molecule
Answer:
C. A linear, nonpolar molecule
Explanation:
Molecules which are alike usually have the same degree of pull which results in them sharing electrons. This sharing of electrons is known as the molecules exhibiting Covalent bonding between them.
The equal pull also results in the cancelling out of electrons and favoring non polar bonds due to the absence of free electrons which would have been able to interact with H2O in a polar binding system.
Answer:
C
Explanation:
APEX
Describe the differences seen in the properties of Boron and Nitrogen.
Answer:
Explanation:
As you move from left to right in periodic table the size of atom size decreases, electrongeativity increases.
it mean
Boron is bigger in size than Nitrogen
Boron is less electroneagive than Nitrogen.
can you find simialr to this another factor to realte
Write Fe salts (divalent Fe)?
Pleasee help.... I will mark the answer with brainlist.
Answer:
Graphitic carbon nitride (g-C3N4) is a rising two-dimensional material possessing intrinsic semiconducting property with unique geometric configuration featuring superimposed heterocyclic sp2 carbon and nitrogen network, nonplanar layer chain structure, and alternating buckling. The inherent porous structure of heptazine-based g-C3N4 features electron-rich sp2 nitrogen, which can be exploited as a stable transition metal coordination site. Multiple metal-functionalized g-C3N4 systems have been reported for versatile applications, but local coordination as well as its electronic structure variation upon incoming metal species is not well understood. Here we present detailed bond coordination of divalent iron (Fe2+) through micropore sites of graphitic carbon nitride and provide both experimental and computational evidence supporting the aforementioned proposition.
How to find the final temperature
Answer:
The final temperature will be "12.37°".
Explanation:
The given values are:
mass,
m = 0.125 kg
Initial temperature,
c = 22.0°C
Time,
Δt = 4.5 min
As we know,
⇒ [tex]q=mc \Delta t[/tex]
On putting the estimated values, we get
⇒ [tex]=0.125\times 22.0\times 4.5[/tex]
⇒ [tex]=12.37^{\circ}[/tex]
Two atoms bonded together will remain some distance apart, minimizing the Question 1 options: A) potential energy of the bond. B) bond distance. C) number of valence electrons in the bond. D) partial charge of the bond. Question 2 (5 points) BeH2 has no lone pairs of electrons. What's the structure of this molecule? Question 2 options: A) Tetrahedral B) Bent C) Octahedral D) Linear Question 3 (5 points) In KCl, how are the valence electrons distributed? Question 3 options: A) The electrons are transferred from K to Cl. B) The electrons are unequally shared between K and Cl, forming a polar covalent bond. C) The electrons are shared between many K and Cl ions, creating a "sea of electrons." D) The electrons are equally shared between K and Cl, forming a covalent bond. Question 4 (5 points) Chlorine can bond with fluorine to form ClF. Chlorine can also bond with lithium to form LiCl. Which compound will have a greater partial charge? Question 4 options: A) Both compounds will have the same partial charge. B) ClF C) LiCl D) Neither compound will have partial charge. Question 5 (5 points) Which of the following elements will not form a polar covalent bond with oxygen? Question 5 options: A) Hydrogen B) Oxygen C) Sodium D) Fluorine Which process is used to produce gases from solutions of salts dissolved in water or another liquid? Question 6 options: A) Electrolysis B) Polar covalent bonding C) Ionic bonding D) Metallic bonding Question 7 (5 points) Saved A chemical reaction has the equation AgNO3 (s) + NaCl (s) → AgCl (s) + NaNO3 (s). What type of reaction occurs between AgNO3 and NaCl? Question 7 options: A) Decomposition B) Double displacement C) Single displacement D) Synthesis
Answer:
1) potential energy of the bond.
2) Linear
3) The electrons are transferred from K to Cl.
4) ClF
5) Oxygen
6) Electrolysis
7) Double displacement
Explanation:
As two atoms approach each other in a bonding situation, the potential energy of the bond is minimized as the internuclear distance of the bonding atoms decreases.
BeH2 has two electron domains and the central beryllium atom is sp2 hybridized. According to valence shell electron pair repulsion theory. A molecule having two regions of electron density will lead to a linear molecule.
KCl is an ionic compound hence there is a transfer of electrons from K(metal) to Cl(nonmetal).
ClF has partial charges because it contains a polar covalent bond. The partial charges arise from the dipole within the molecule. LiF is a pure ionic compound formed by transfer of electrons from Li to F. The species possess full and not partial charges.
When an oxygen atom bonds with another oxygen atom, what has been formed is a homonuclear covalent bond. Since the electro negativity of the both atoms is exactly the same, a pure covalent bond is formed. Recall that polar covalent bonds are formed when there is a significant electro negativity difference between the bonding atoms.
When direct current is passed through certain salt solutions during electrolysis, gases may be evolved and collected at the appropriate electrodes.
A double-replacement reaction is a reaction in which the cations and anions present in two different ionic compounds that are reacting together exchange their positions to form two new compounds on the product side. For instance, look at the reaction shown in question 7 as a typical example of this;
AgNO3 (s) + NaCl (s) → AgCl (s) + NaNO3 (s).
I NEED HELP PLEASE, THANKS! :)
Combustion reactions are a notable source of carbon dioxide in the environment. Using the following balanced equation, how many grams of carbon dioxide are formed when 100.00 g of propane (C3H8) is burned? Express your answer to the correct number of significant figures.
Answer:
[tex]\large \boxed{\text{299.4 g}}[/tex]
Explanation:
We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.
Mᵣ: 44.10 44.01
C₃H₈ + 5O₂ ⟶ 3CO₂ + 4H₂O
m/g: 100.00
To solve a stoichiometry problem, you must
Use the molar mass to convert mass of C₃H₈ to moles of C₃H₈ Use the molar ratio to convert moles of C₃H₈ to moles of CO₂ Use the molar mass to convert moles of CO₂ to mass of CO₂
1. Moles of C₃H₈
[tex]\text{Moles of C$_{3}$H}_{8} = \text{100.00 g C$_{3}$H}_{8} \times \dfrac{\text{1 mol C$_{3}$H}_{8}}{\text{44.10 g C$_{3}$H}_{8}} = \text{2.268 mol C$_{3}$H}_{8}[/tex]
2. Moles of CO₂
The molar ratio is 3 mol CO₂:1 mol C₃H₈
[tex]\text{Moles of CO}_{2} = \text{2.268 mol C$_{3}$H}_{8} \times \dfrac{\text{3 mol CO}_{2}}{\text{1 mol C$_{3}$H}_{8}} = \text{6.803 mol CO}_{2}[/tex]
3. Mass of CO₂
[tex]\text{Mass of CO}_{2} = \text{6.803 mol CO}_{2} \times \dfrac{\text{44.01 g CO}_{2}}{\text{1 mol CO}_{2}} = \textbf{299.4 g CO}_{2}\\\text{The mass of CO$_{2}$ required is $\large \boxed{\textbf{299.4 g}}$}[/tex]
Answer:
Number of moles of propane:
=Mass in grams ÷ Relative molecular Mass
= 100/((12*3) + (1*8))
= 100 ÷ 44
= 2.2727
Mole ratio propane:carbon (IV) oxide = 1:3(from the equation)
Number of moles of CO2 = 3*2.2727 = 6.8181
Mass in grams = Relative molecular Mass * Number of moles
= 44 * 6.8181
= 299.9964 grams
Explanation:
HELP!!!!!!!!!!!!!!!! PRETTY PLEASE !!!!!!!!!!!!!!!!
Answer:
B. 75.0 kPa
Explanation:
P1V1/T1=P2V2/T2
(x * 100 L)/(300 K)=(100 kPa * 50.0 L)/(200 K)
x=75.0 kPa
Answer:
24rq3r54
Explanation:
3t5q6tq6tq
Lulu Labwrecker carefully pipets 25.0 mL of 0.525 M NaOH into a test tube. She places the test tube into a small beaker to keep it from spilling and then pipets 75.0 mL of 0.355 M HCl into another test tube. When Lulu reaches to put this test tube of acid into the beaker along with test tube of base she accidentally knocks the test tubes together hard enough to break them and their respective contents combine in the bottom of the beaker. Is the solution formed from the contents of the two test tubes acidic or basic? What is the pH of the resulting solution?
Answer:
The solution formed is acidic
pH = 0.87
Explanation:
The acid-base reaction of NaOH with HCl is:
NaOH + HCl → NaCl + H₂O
Where 1 mole of NaOH reacts with 1 mole of HCl
In the problem, moles of NaOH and HCl are:
NaOH: 0.0250L × (0.525mol / L) = 0.013125 moles NaOH
HCl: 0.0750 × (0.355mol / L) = 0.026625 moles HCl
As moles of HCl > moles NaOH, HCl is in excess and the solution formed is acidic
Moles in excess of HCl are:
0.026625 moles - 0.013125 moles = 0.0135 moles HCl
As the volume of the solutions is 25.0mL + 75.0mL = 100.0mL = 0.100L, molarity of HCl after reaction is:
0.0135 moles HCl / 0.100L = 0.135M HCl = 0.135M H⁺
As pH is defined as - log [H⁺], pH of the solution is:
pH = -log 0.135M H⁺ = 0.87
pH = 0.87
The pH of the resulting solution of the acid and base mixture is; Acidic with a PH = 0.87
We are given;
Volume of NaOH = 25 mL = 0.025 L
Volume of HCl = 75 mL = 0.075 L
Concentration of NaOH = 0.525 M
Concentration of HCl = 0.355 M
Total volume of solution = 0.025 + 0.075 = 0.1 L
Now, the the equation of the reaction is;
HCl + NaOH = NaCl + H2O
We can see that 1 mole of HCl reacts with 1 mole of NaOH.
Since; number of moles = Volume × concentration
Number of moles of HCl = 0.075 × 0.355
Number of moles of HCl = 0.026625 moles
Similarly;
Number of moles of NaOH = 0.025 × 0.525
Number of moles of NaOH = 0.013125 moles
We can see that the number of moles of HCl is greater than that of NaOH and as such there is excess HCl acid in the mix.
Thus,
Excess moles of HCl acid = 0.026625 - 0.013125
Excess moles of HCl acid = 0.0135 moles
Concentration of this excess HCl is gotten by the formula;
M = Excess moles/total volume
M = 0.0135/0.1
M = 0.135 M
PH of this excess concentration is;
PH = -log [H+]
PH = -log [0.135]
PH = 0.87
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What volume will be occupied by 11.7 g of Helium in a balloon at an altitude of 10.0 km if the air pressure is 0.262 atm and the temperature is -50.0 °C?
Answer: 204 L
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 0.262 atm
V = Volume of gas = ?
n = number of moles = [tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{11.7g}{4g/mol}=2.92[/tex]
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]-50^0C=(273+(-50))K=223K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{2.92\times 0.0820 L atm/K mol\times 223K}{0.262atm}=204L[/tex]
Thus volume occupied by 11.7 g of Helium in a balloon is 204L
The disinfectant hydrogen peroxide (H2O2)
decomposes to form water and oxygen gas.
How much O2 will result from the decomposition of 2.22 mol of hydrogen peroxide?
Answer:
1.1 mol of O2
Explanation:
First we need the balance chemical equation which is
2 H2O2 -------> 2 H2O + O2
This is important because in stoichiometry you can go from units of one thing to other by using mole ratios, here the mole ratio is 2 mol of H2O2 for one mole of O2.
[tex]2.2 mol H2O2 \frac{1mol O2}{2 mol H2O2}[/tex] = 1.1 mol of O2
A 20 mL volume of a hydrochloric acid solution, HCl (aq), was placed into a beaker containing an appropriate
acid-base indicator. It was titrated with a solution of sodium hydroxide, NaOH (aq), until the endpoint was
reached. If 25 mL of sodium hydroxide solution with a concentration of 0.20 mol/L was used, what is the
concentration of the acid?
Select one:
a. 2.5 mol/L
O
b. 0.20 mol/L
C. 0.25 mol/L
d. 2.0 mol/L
Answer:
C- 0.25mol/L
Explanation:
Hcl+Naoh-Nacl+H2O
Ratio =1:1
0.2moles of Naoh in1000cm3 what about 25=(25×0.2)÷1000=
0.005moles
0.005moles in 20cm³ what about in 1000
(0.005×1000)÷20=0.25mol/L
According to the molar concentration, the concentration of the acid is 2.5 mole/liters.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions, molar concentration is obtained as M₁V₁=M₂V₂, on substitution of values, M₁=25×0.20/20=2.5 mole/L.
Thus,the concentration of the acid is 2.5 mole/liters.
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7) Put the following molecules in order of where they would be found in the fractional distillation
column (from bottom to top). Hexane, Octane, Ethane, Dodecane, Decane, Methane
FAST
Answer:Crude oil is a mixture of many saturated hydrocarbons. They can be separated into fractions by the process of fractional distillation.
Explanation:
The octane number of fuel is 79%. What does that mean
Answer:
Octane number, measure of the ability of a fuel to resist knocking when ignited in a mixture with air in the cylinder of an internal-combustion engine.
Octane number is also known as octane rating. Octane numbers are based on a scale on which isooctane is 100 (minimal knock) and heptane is 0 (bad knock). The higher the octane number, the more compression required for fuel ignition. Fuels with high octane numbers are used in high performance gasoline engines.
(Hope this helps) Sky
Explain why covering something with a blanket can put out a fire
Answer:
No oxygen
Explanation:
when something is covered in a blanket it prevents the fire from being able to have any oxygen
Answer:
Its called smothering the fire
Explanation:
A fire needs three things to burn always: fuel, oxygen, and a heat source. Eventually the heat source will not be an issue, but the oxygen and fuel is. If the fire is small enough throwing a blanket can quite smother it. What happens is it cuts off the oxygen supply the fire needs long enough for it to die out.
A student places a 12-gram cube of Ice Inside a container. After six hours, the student returns to observe the contents of the container. Which
sentence suggests that the container is an open system?
ОА
The container contains 12 grams of liquid water and no ice.
B.
The container contains 12 grams of Ice and no liquid water.
D.
The container contains 8 grams of liquid water and no ice.
The container contains 8 grams of ice and 4 grams of liquid water.
The container contains 8 grams of liquid water and 4 grams of water vapor.
E
Answer:
I think its D sorry if im wrong
Answer:i think its D
Explanation:
What is the answer to this ?
Answer:
12.78 or 12.80 mostly like 12.78
Explanation:
