[問題]PREP-T1-Q182

[oneseven]

In a certain year, the difference between Mary's and Jim's annual salaries was twice the difference between Mary's and Kate's annual salaries. If Mary's annual salary was the highest od the 3 people, what was the average (arithmetic mean) annual salary of the 3 people that year?

(1) Jim's annual salary was $30,000 that year.

(2) Kate's annual salary was $40,000 that year.

Answer: B

但是我選C 我覺得兩個合起來 (M-30000) = 2(M-40000) 才有辦法求解??

是我漏了什麼嗎 幫幫忙 謝謝

[eced]

題目給 M-J=2(M-K) 求 (M+J+K) /3
由題目得 M-J=2M-2K 2K=M+J AVE=3K/3 =K
知道K就能得解

[oneseven]

哀哀 ...真的是太粗心了
謝謝你