菜鸟问下og上的 word problem sets example 2

crown48

论坛上没搜到，估计是这题太弱智了。。。
求好心人帮忙


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.


求下总数

sdcar2010

Total toys = N
0.4*N = red; 0.6*N = green.
0.5*N = small; 0.5*N = large.
0.1*N = red and small.
40 = green and large.

If 0.1*N = red and small, then 0.3*N = red and large, then 0.2*N = green and large.

If 40 = green and large, then N = 40/0.2 = 200.

Then red and large = 200*0.3 = 60.