SOLUTION: Alonzo's gas tank is 3/10 full. After he buys 10 gallons of gas, it is 4/5 full. How many gallons can Alonzo's tank hold?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Alonzo's gas tank is 3/10 full. After he buys 10 gallons of gas, it is 4/5 full. How many gallons can Alonzo's tank hold?       Log On


   

Question 276702: Alonzo's gas tank is 3/10 full. After he buys 10 gallons of gas, it is 4/5 full. How many gallons can Alonzo's tank hold?

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!


Let's illustrate the tank to help us in the problem:
----> "+" 10 gal --->

Putting the scenario into equation:
%283%2F10%29%28x%29%2B10gal=%284%2F5%29%28x%29
10=%284%2F5%29%28x%29-%283%2F10%29%28x%29%0D%0A%7B%7B%7B10=%28x%29%284%2F5-3%2F10%29
10=%28x%29%28%288-3%29%2F10%29
10=%28x%29%285%2F10%29=%28x%29%281%2F2%29
highlight%28x=2%2A10=20gal%29, Answer (full tank)

Check:
1st scenario
(3%2F10) full = %283%2F10%29%2820%29=60%2F10=6gal
2nd scenario: added 10 gal:
6gal%2B10gal=16gal

--> 16gal%2F20gal=4%2F5

Thank you,
Jojo