《费费数学宝典》第30题讨论

justdo665

第30题：5天内5次测温度，average是50度，最小是45度，问最大可能的range？

请问：解题思路？

simkeechai

i think that five days five readings, average is 50 degrees, minimum is 45 derees.

since you have five readings, and minimum is 45 degrees; you can assume that you have four readings with 45 degrees, and the last reading be 70, so the largest possible range for this is 25 degree.

catttt

因为average是固定的，所以当其他4个数字越小，最大的数字就越大，range就越大，

所以令中间的3个数都等于min，则max＝50×5－45×4＝70，

所以最大的range就是70－45＝25

justdo665

明白了，谢谢！