Question

QUICK HELP!!!!

Justin's gas tank is 1/6 full. After he buys 7 gallons of gas, it is 1/2 full. How many gallons can Justin's tank hold?

Answer 1

21 gallons

Explanation:

The tank is half full after the 7 gallons goes into it. It started with 1/6 of a tank. 1/2 - 1/6 = 1/3. That means that it took 7 gallons to fill that 1/3. We can use proportions now to solve this:

`(gallons)/(tank):(7)/((1)/(3) )=(x)/(1)`

where x is the number of gallons when the tank is full (1). Cross multiply to get:

`(1)/(3)x=7` so

x = 21 gallons