When n liters of fuel was added to a tank that was already 1/3 full, the tank was filled to 5/9 of its capacity. In terms of n, what is the capacity of the tank, in liters?
Options:
A) 10/9 n  B) 4/3 n  C) 9/2 n  D) 9/4 n  E) 7/3n
C is the answer.   To solve this problem, draw diagram or use algebra. I'm more comfortable with algebra.   Given   - tank was already 1/3 full.   - When n ltr added, it became 5/9   So 1/3 + n = 5/9   n = 5/9 - 3/9   n = 2/9   capacity of the tank is full fraction . i.e. 1 i.e. 9/9   so the question is 9/9 is how much times n   = 9/9= 
<gadget id="calculator">9/9</gadget>
<output>1</output>
1= xn   so x = 9/2   and total = 9/2n
<result>C</result>
When n liters of fuel was added to a tank that was already 1/3 full, the tank was filled to 5/9 of its capacity. In terms of n, what is the capacity of the tank, in liters?