大牛，帮帮忙！！（钱永强的一条例子题）

Mush

In a certain production lot, 40 percent of the toys are red and the remaining toys are green. Half of the toys are small and half are large. If 10 percent of the toys are red and small, and 40 toys are green and large, how many of the toys are red and large.

她最后算出来是20个。可是我怎么算都是60个。
思路如下
rs=red and small
rl=red and large
gs=green and small
gl=green and large

rs+rl=40%, rs=10% =====>rl=30%
rs+gs=50%====>gs=40%, gs+gl=1-40%====>gl=20%

gl有40个，gl的比例是20%，rl的比例是30%，所以得出rl的数目为60。 我错了吗？

tongxun

red       green      total
small        10%        40%       50%

large        x          40        50%

total      40%         60%        100%  
40=I*20%,=>I=200=>x=200*30%=60
I agree with your answer.

isenetlab12

I think  u r right.