Multiple-Choice, Multiple Answers on the GRE Math Test — Practice Questions - dummies

Multiple-Choice, Multiple Answers on the GRE Math Test — Practice Questions

By Ron Woldoff, Joseph Kraynak

Although math questions typically have only one right answer, this isn’t always the case. As a result, some multiple-choice questions on the GRE Math test will give you a list of answers and ask you to choose more than one.

The following practice questions ask you to find different possible values in a sequence and the different perimeters for a triangle, given two sides.

Practice questions

  1. In the given sequence a1, a2, a3, a4, a5, …, an, where a1 = 2, n is a positive integer, and an+1 = 3an + 2, which of the following could be a value of an?

    Select all that apply.

    A. 2

    B. 6

    C. 8

    D. 10

    E. 26

    F. 28

  2. The lengths of two sides of a triangle are 5 and 7. Which of the following could be the perimeter of the triangle?

    Select all that apply.

    A. 14

    B. 17

    C. 19

    D. 22

    E. 24

    F. 27

Answers and explanations

  1. A, C, E

    Use the formula to find a2 by substituting a1 for an and a2 for an + 1. Now the formula becomes a2 = 3a1 + 2. Because a1 = 2, a2 = 3(2) + 2, or 8. Do this again with the next few values of a, up to and through 28, because that’s the highest number; a3 has a value of 26, which makes a4 have a much greater value than anything in the list.

  2. B, C, D

    With two sides equaling 5 and 7, the third side has to be between 2 and 12, not inclusive. This places the perimeter between 14 and 24, again not inclusive. Only three of the numbers fall within that range.