Rectangular Floors X and Y have equal

Another approach would be the "doubling and halving technique", explained here: http://gmat.magoosh.com/lessons/311-doubling-and-halving

D&H technique: A·B = (A/2) · 2B

Since 18 · 12 = 9 · L
(9 · 2) · 12 = 9 · (12 · 2)

Since 12 · 2 = 24, correct answer is 24 (E).

Jan 24, 2015 • Comment

Mike McGarry, Magoosh Tutor

Dec 26, 2013 • Comment