Chart Word Problem GMAT, GRE Quant

A shoe cobbler charges n dollars to repair a single pair of loafers. Tomorrow, he intends to earn 240 dollars repairing loafers. If he were to reduce his fee per pair by 20 dollars, he would have to repair an additional pair of the loafers to ear the same amount of revenue. How many pair of loafers does he intend to repair tomorrow?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Overlapping Sets, GMAT GRE Question

Each of the items in a box is either a ball or a cube and each item is either red or blue. 72% of the items are cubes and 54% of the items are blue cubes. What percent of the cubes are red?

(A) 18%
(B) 25%
(C) 46%
(D) 50%
(E) 54%

Variables in Answer Choices with Distance Rate Time GMAT Problem

If Susan takes 9 seconds to run y yards, how many minutes will it take her to run x yards at the same rate?

A certain calculating machine has only three operation buttons, D, R and A. The D operation doubles the number the machine displays, the R operation subtracts 1 from the number the machine displays, and the A operation adds 1 to the number the machine displays. If the machine initially displays the number 2, which of the following operation sequences (read from left to right) would lead to the same final displayed result as the sequence - D R D R D R D R D R D R ?

A. D D D D D D R R R R R R

B. R D R D R D R D R D R D

C. A D D D D D

D. D D D D D A

E. D D D D D D D A