SAT Math Multiple Choice Practice Question 301: Answer and Explanation
15. If a, b, and c are consecutive positive integers such that and abc is NOT a multiple of 4, then which of the following must be true?
A. a is even
B. b is even
C. c is even
D. a + b + c is odd
E. abc is odd
Correct Answer: B
B The only way that abc would not be a multiple of 4 is if none of the three numbers is a multiple of 4 and no two of them are even (because the product of two evens is always a multiple of 4). One simple example is , , and . This example rules out choices (A), (C), (D), and (E).