PSAT Math : How to add even numbers

Study concepts, example questions & explanations for PSAT Math

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Example Questions

Example Question #651 : Arithmetic

If x represents an even integer, which of the following expressions represents an odd integer?

Possible Answers:

5x + 4

x + 2

2x – 2

3x + 1

3x – 2

Correct answer:

3x + 1


Pick any even integer (2, 4, 6, etc.) to represent x. The only value that is odd is 3x + 1. Any number multiplied by an even integer will be even. When an even number is added and subtracted to that product, the result will be even as well. 3x + 1 is the only choice that adds an odd number to the product.

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