Simon's water cooler can hold up to 4.2 gallons of water in it. Simons fills the cooler so that there is water in all but 25% of the cooler. How much more water would Simon need to add to fill the entire 100% of the cooler?
A 1.05 gallons
B 3.95 gallons
C 3.15 gallons
D 1.7 gallons
Based on the information given we know that 75% of the cooler is filled, because 25% is left. We only need to know what 25% of 4.2 is though, because the question is asking how much more he would need. 25% of 4.2 is equal to .25*4.2 which equals 1.05. So in this scenario, the correct answer would be A.
