SAT Math Multiple Choice Practice Question 496: Answer and Explanation
16. If a = 4b + 26, and b is a positive integer, then a could be divisible by all of the following EXCEPT
Correct Answer: B
B To find out what numbers a could be divisible by, you need to try different values of b. If b = 1, then a = 4(1) + 26 = 30. In this case, a is divisible by 2, 5, and 6, so you can cross out A, C, and D. If b = 4, then a = 42, which is divisible by 7, so cross out E. That leaves only B, which must be the answer.