PSAT Math Multiple-Choice Question 778: Answer and Explanation

Question: 778

The table omits the value for x in the bottom row. Based on the structure of the table, what is the value of x?

• A. 24
• B. 38
• C. 57
• D. 65

Correct Answer: D

Explanation:

(D) Look at the bottom row. There are a total of 400 individuals. Each person selected the one type of communication that he or she prefers. So the first four numbers in the bottom row must add up to 400:
195 + x + 70 + 70 = 400
Combine like terms on the left side of the equation:
335 + x = 400
Subtract 335 from both sides to isolate x:
x = 65
The answer is choice (D).
Alternatively, you could have added the first two terms in the e-mail column to obtain x:
20 + 45 = 65.