GMAT, GRE Math Word Problem

Elmer, the circus Elephant, is currently three times older than Leo, the circus Lion. In five years from now, Leo the circus Lion will be exactly half as old as Elmer, the circus Elephant. How old is Elmer today?

A) 10
B) 15
C) 17
D) 22
E) 25

Remainders Number Properties Question GMAT, GRE

What is the remainder when 1555 * 1557 * 1559 is divided by 13?

(A) 0
(B) 2
(C ) 4
(D) 9
(E) 11

Number Properties Min/Max GMAT Problem

What is the greatest possible common divisor of two different positive integers which are less than 144?

A. 143
B. 142
C. 72
D. 71
E. 12