Read the following SAT test question, then click on a button to select your answer.

All numbers divisible by both 4 and 15 are also divisible by which of the following?

  1. 6
  2. 8
  3. 18
  4. 24
  5. 45

 

 

Correct Answer: A

Here's Why:

“Divisible by” means that the remainder is zero after the division. For example, 8 is divisible by 4, but it is not divisible by 3, since dividing 8 by 3 leaves a remainder of 2.

First, find a number that is divisible by both 4 and 15. One such number is 60. Now check each choice to see if 60 is divisible by that choice. 60 is divisible by choice A, but it is not divisible by any of the other choices. Therefore, this choice, 6, must be the correct answer.

When the arithmetic is simple and you understand what the question is asking, it’s okay to find the answer by:

  • checking each choice
  • eliminating choices

In more complicated problems, however, this can take more time than finding a solution through mathematical reasoning.

Difficulty: Medium

Question Type: Standard Multiple Choice