When n liters of fuel was added to a tank that was already 1/3 full, the tank was filled to 7/3 of its capacity. In terms of n, what is the capacity of the tank, in liters?
Choose the correct option
A) 1/2 n  B) 4/3 n  C) 3/2 n  D) 9/4 n  E) 7/3n
A 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 7/3   So 1/3 + n = 7/3   n = 7/3 - 1/3   n = 6/3   capacity of the tank is full fraction . i.e. 1 i.e. 3/3   so the question is 3/3 is how much times n   = 3/3= 
<gadget id="calculator">3/3</gadget>
<output>1</output>
1= xn   so x = 3/6   and total = 3/6n=1/2n
<result>A</result>
When n liters of fuel was added to a tank that was already 1/3 full, the tank was filled to 7/3 of its capacity. In terms of n, what is the capacity of the tank, in liters?