GRE GEOMETRY QUESTION OF THE DAY

The bottom of an underground rectangular tank has
an area of 12 square feet and the depth of the tank is
10 feet. A liquid is pumped into the empty tank at
the constant rate of 30 cubic feet per minute. After
how many minutes will the depth of the liquid in the
tank be 8 feet?
(A) 1.5
(B) 2.0
(C) 2.5
(D) 3.2
(E) 4.0