Question of the Day

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3/14 , 5/2

Mar
5
2015
16,859 responses
Question of the Day Statistics
Number Answered
Correct 10,983
Incorrect 5,876
65% correct

Mathematics > Standard Multiple Choice

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

Add 8 times x to 2 times x and then subtract 5 from the sum. If x is a positive integer, the result must be an integer multiple of

Answer Choices

Hint

It may be helpful to write out mathematically the expression that is given in words in the question. Then see which of the answers must be a factor of the number represented by the expression in x.

Question of the Day

Can you answer today's question?

Register Next Tests:
3/14 , 5/2

Mar
5
2015
16,859 responses
Question of the Day Statistics
Number Answered
Correct 10,983
Incorrect 5,876
65% correct

Mathematics > Standard Multiple Choice

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

Add 8 times x to 2 times x and then subtract 5 from the sum. If x is a positive integer, the result must be an integer multiple of

Answer Choices

Answer

The mathematical expression given in the question is (8 times x) + (2 times x) minus 5, which is equivalent to (10 times x) minus 5. The expression (10 times x) minus 5 can be factored as 5 times ((2 times x) minus 1). For every positive integer x, 5 times ((2 times x) minus 1) must be a multiple of 5. If x = 1, then 5 times ((2 times x) minus 1) = 5, which is not an integer multiple of  2, 8, 10, or 15. Therefore, the correct answer is 5.