皮皮学，免费搜题
登录
搜题
【简答题】
盒中装有8个乒乓球，其中6个是没有用过的，2个是用过的． （Ⅰ）从盒中2个球使用，求恰好取出1个用过的球的概率； （Ⅱ）若从盒中2个球使用，用装回盒中，求此时盒中恰好有4个是用过的球的概率．
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】For each blank, choose the best answer from the four choices and write down on the answer sheet. (71) is a channel's capacity which directly reflects the data transfer rate of the channel. (72) is an ...
A.
The delay
B.
The volume
C.
The noise
D.
The bandwidth
【简答题】Complete the sentences with the words below. Change the form where necessary. [administrative volunteer meticulous instruct thoroughly registration] 1 Communicatio...
【单选题】Which one is the main idea of the passage?
A.
Smartphones have improved people’s lives and been helpful in a variety of things.
B.
Personal safety takes a back seat when it comes to smartphone usage while driving.
C.
There is a negative inf luence that smartphones have introduced into people’s lives.
D.
The increased use of smartphones has probably reduced human interaction, affecting more than just verbal communication.
【单选题】Which of the following is not the qualities of good inf o rmation?
A.
relevance
B.
completeness
C.
appropriate communication
D.
materiality
相关题目：