这个数学题怎么做?

xiaolichina · Jul 20th, 2004, 19:27

4.1 班有46人，会钢琴的有30人，小提琴的有28人，这个班
会钢琴的又会小提琴的有多少人？

robatel2002 · Jul 20th, 2004, 20:27

12 to 28

xiaolichina · Jul 21st, 2004, 07:48

12 or 28?

Standby · Jul 21st, 2004, 08:31

Easy! The only answer is 12. 30+28-46=12.

You can draw a Venn diagram to help you figure it out.

djccn · Jul 21st, 2004, 08:41

引用:

作者: Standby

Easy! The only answer is 12. 30+28-46=12.

You can draw a Venn diagram to help you figure it out.

from 12 to 28, the answer is not only one number.

prolog · Jul 21st, 2004, 08:53

Its 12 if you assume every student knows at least one instrument

Standby · Jul 24th, 2004, 18:01

Yes, what you said is more precise.

If there are some students in the class who can neither play piano nor violin, then there will be more than one answer (17 probabilities: 12 to 28). But if everyone in the class can play either piano or violin, then there will be only one answer (12).

Actually, the latter is more likely.

引用:

作者: prolog

Its 12 if you assume every student knows at least one instrument

六里台 · Jul 26th, 2004, 14:10

我记得小学的时候数学课上有过这么一道题，原话是：乐器班有46个人...

血蛤蟆 · Jul 26th, 2004, 14:17

引用:

作者: prolog

Its 12 if you assume every student knows at least one instrument

原文可是没有这个假设，所以是一道狗屁数学题！害得我想了老半天！

六里台 · Jul 26th, 2004, 14:20

原题该是“乐器班”，这样就说明每个人都至少会一样乐器了

robatel2002 · Jul 27th, 2004, 17:56

u r right

引用:

作者: djccn

from 12 to 28, the answer is not only one number.

Jul 20th, 2004, 19:27	#1
xiaolichina Senior Member 注册日期: Jul 2004 帖子: 1,603	这个数学题怎么做? 4.1 班有46人，会钢琴的有30人，小提琴的有28人，这个班会钢琴的又会小提琴的有多少人？
xiaolichina Senior Member 注册日期: Jul 2004 帖子: 1,603

Jul 20th, 2004, 20:27	只看该作者 #2
robatel2002 Senior Member 注册日期: Jul 2004 帖子: 346 声望: 48	12 to 28
robatel2002 Senior Member 注册日期: Jul 2004 帖子: 346 声望: 48

Jul 21st, 2004, 08:31	只看该作者 #4
Standby Senior Member 注册日期: Jul 2004 帖子: 393 声望: 140425	Easy! The only answer is 12. 30+28-46=12. You can draw a Venn diagram to help you figure it out.
Standby Senior Member 注册日期: Jul 2004 帖子: 393 声望: 140425

Jul 21st, 2004, 08:53	只看该作者 #6
prolog Member 注册日期: Jul 2004 帖子: 98 声望: 0	Its 12 if you assume every student knows at least one instrument
prolog Member 注册日期: Jul 2004 帖子: 98 声望: 0

Jul 21st, 2004, 07:48	只看该作者 #3
xiaolichina Senior Member 注册日期: Jul 2004 帖子: 1,603 声望: 22611	12 or 28?

Jul 26th, 2004, 14:10	只看该作者 #8
六里台 Joe的马甲注册日期: Jul 2004 帖子: 24,120 积分:30 精华:11 声望: 2147483647	我记得小学的时候数学课上有过这么一道题，原话是：乐器班有46个人...

Jul 26th, 2004, 14:20	只看该作者 #10
六里台 Joe的马甲注册日期: Jul 2004 帖子: 24,120 积分:30 精华:11 声望: 2147483647	原题该是“乐器班”，这样就说明每个人都至少会一样乐器了