GRE-Style: 3D Volume Problems

GRE Quantitative · Axiom Academy

EXAMPLE GRE-Style: 3D Volume Problems Solving for a missing dimension when the volume is already known A cylindrical water tank has a volume of cubic feet. The tank's radius is 4 feet. What is the height of the tank, in feet? Cylinder with radius 4 ft — height is the unknown we're solving for. Nice work — you solved a GRE-style volume problem in reverse, finding a missing dimension from a given volume. Know the formula cold: the volume of a cylinder is — never a lateral-surface-area formula like . Isolate before you substitute: solving first avoids arithmetic slips. Watch radius vs. diameter: the GRE often gives one and expects you to recognize which — squaring the wrong value is the most common trap. This "solve for the missing dimension" pattern shows up constantly on the GRE — boxes, cylinders, and cubes alike. Master isolating the unknown first, and the substitution takes care of itself.

This is the written version of the interactive lesson above. See the full GRE Quantitative course.