Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition
AB
x BA
The product of the two-digit numbers above is the three-digit number ACA, where A, B and C are three different nonzero digits. If A x B <10, what is the two-digit number AB?
(A) 11
(B) 12
(C) 13
(D) 21
(E) 31
While plugging answer choices is good way to attack this question, it is good to leverage some facts given in the question stem first, so that we need to try out only a few choices.
1) Units digit of AB*BA is A.
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