GRE Sample Test 2 Quantitative Reasoning 2

Plug In! Let’s say that the height is 10, the depth is 20, and the width is 20. If the height is increased by 20%, the new height is 12. If the depth is decreased by 20%, the new depth is 16 and the width remains 20.
The new volume is 12 × 16 × 20 = 3,840. If you use those same numbers but make the changes by 40%, the new volume is 14 × 12 × 20 = 3,360. Quantity A is greater. However, make sure you switch the numbers to check all possibilities. Make the height 20, the depth 10 and the width 20. If p is 20, the volume of the new 3D figure is 24 × 8 × 20 = 3,840. If p is 40, the volume of the new 3D figure is 28 × 6 × 20 = 3,360. The quantities are the same regardless of what numbers you Plug In. The answer is (A).