和冰墩墩一起挑战奥数，打卡第七天

趁冬奥东风，「小留洋」策划10期奥数挑战，每日一道奥数题，评论区每天打卡并参与讨论，坚持10天将获得我们整理的新加坡奥数资料集锦电子版。

昨日试题解析

[英文原题]Una rolls 6 standard 6-sided dice simultaneously and calculates the product of the 6 numbers obtained. What is the probability that the product is divisible by 4？

中文释义如下，Una同时掷6个6面骰子，得到6个数，计算6个数的乘积，问，这个乘积被4整除的概率是多少？

可以考虑乘积不能被4整除的概率，然后1-不能被4整除的概率=乘积能被4整除的概率。

乘积不能被4整除可以分为2种情况：

情形1: 乘积不能被2整除。一个骰子掷出奇数的概率为1/2，6个骰子都是奇数的概率是1/64.

情形2：乘积能被2整除，但不能被4整除。需要5个骰子为奇数，一个骰子为偶数。概率为

答案为1-（1/64+1/16）=59/64.

今日试题

A scientist walking through a forest recorded as integers the heights of 5 trees standing in a row. She observed that each tree was either twice as tall or half as tall as the one to its right. Unfortunately some of her data was lost when rain fell on her notebook. Her notes are shown below, with blanks indicating the missing numbers. Based on her observations, the scientist was able to reconstruct the lost data. What was the average height of the trees, in meters?

本专题由小留洋小鱼爸爸编写，关注「小留洋」，获取更多海外教育资料。