11

Werner wrote a list of numbers with sum 22 on a piece of paper. Ria then subtracted each of Werner’s numbers from 7 and wrote down her answers. The sum of Ria’s numbers was 34. How many numbers did Werner write down?

A 7 B 8 C 9 D 10 E 11

Answer

B

SOLUTIOn

For each number n that Werner wrote down, Ria wrote 7 − n. Therefore, the sum of one of Werner’s numbers and Ria’s corresponding number is 7. Since the total of all Werner’s numbers and all of Ria’s numbers is 22 + 34 = 56, the number of numbers that Werner wrote down is 56 ÷ 7 = 8.

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