求助。JJ121

xmlvivian

121.做A,B,C三件事情的人数比例是62%，48%，32%，大概是这个数，总人数是1200人，告诉了既没做A也没做B的比例是30%，好像问的是只做C的做大值吧。

sdcar2010

Well, the number of people who ONLY do C would be no biggger than the people who do neither A nor B, because the latter number equals the sum of the former number and those who do NOTHING at all.

To find the biggest possible value for C, you only need to assign all those do neither A nor B to complete C.  1200*0.3 = 360