It took 12 gallons of gas to fill the tank of the family car. This is five sixths of the amount the tank can hold. How much gas does the tank hold?

A. 10 gallons
B. 14two fifths gallons
C. 12five sixths gallons
D. 13five sixths gallons

If 12 gallons is five sixths of the tank, then we can set up a proportion:

12/x = 5/6

To solve for x (the total amount the tank can hold), we can cross-multiply:

12 * 6 = 5 * x

72 = 5x

x = 72/5

x = 14.4 gallons

So the tank can hold 14.4 gallons, which is closest to choice B: 14two fifths gallons.

or, simply ....

(5/6)x = 12
x = 12(6/5) = 72/5 = 14.4 gallons