[問題]新pp問題4

[mht]

4.Five piece of wood have an average (arithmetic mean)length of 124 centimeters and a median length of 140 centimeters. What is the maximum possible length, in centimeters, of the shortest piece of wood?

Ans. 100

[clbb]

我只想到笨方法，假設五根木頭由低到高依序為A,B,C,D,E

A+B+C+D+E=124*5=620

C=140 所以 A+B+D+E=620-140=480

又C是中數，所以D+E>=140*2=280

故A+B<=480-280=200

所以A最大的可能為A=B=100