Posted by Jen on Wednesday, March 23, 2011 at 7:31pm.
let x = number of gallons the when tank is full
according to first statement, initially the tank is 1/5 full. thus we can write it as (1/5)x
according to second statement, he bought 6 gallons, thus we add 6 to the initial amount, and it becomes 7/10 full or (7/10)x
rewriting using equations:
(1/5)x + 6 = (7/10)x
solving for x,, first we multiply both sides of the equation by 10 to get rid of denominators and deal with whole numbers:
10*(1/5)*x + 6*10 = 10*(7/10)*x
2x + 60 = 7x
60 = 5x
x = 12 gallons
hope this helps~ :)
Related Questions
math - Justin's gas tank is 1/4 full. After he buys 9 gallons of gas, it is ...
math - Josh's gas tank is 1/5 full. After buying 7 gallons it is 7/10 full. ...
math - The gas tank in Micheal's car can hold 18.0 gallons. If the tank ...
Math - A gas tank is 1/4 full. Abby adds 4 gallons and now it is 5/8 full. How ...
algebra - while driving a car you realize that you only have one eighth gas ...
math - 1. Jina purchased a prepaid phone card for $15. Long distance calls cost ...
math - the gas tank of your car holds 21 gallons. It is 1/3 full. How many ...
math - the gas tank in bob's car holds at most 15 gallons. He has already ...
math - suppose that the gas tank of a car holds 12 gallons and that the car uses...
Math - Added 5 gallons of gas tank went from 3/8 full to 7/8 how big is tank
For Further Reading
