GWD-11-17

creativity

Q17:

A certain list consists of 21 different numbers. If n is in the list and n is 4 times the average (arithmetic mean) of the other 20 numbers in the list, then n is what fraction of the sum of the 21 numbers in the list?

A. 1/20

B. 1/6

C. 1/5

D. 4/21

E. 5/21

求教，没有头绪。

himba

ave of ther other 20 numbers = n/4 , n is what fraction of the sum of the 21 numbers in the list = n / (n + n/4 * 20) = 1/6. The answer is B.

creativity

多谢解答！！！[em07]