How many of the boys in a group of 100 children have brown hair?

1)Of the children in the group,60 percent have brown hair.

2) Of children in the group ,40 are boys

答案是E。这个不是A吗？？？？而且他的解析我觉得有问题，是否这个题目答案有问题？？？

解释说道：1）only the total number of children have who have brown hair can be determined,so statement alone is not sufficient.

???/题目不就是问在100个小孩中，brown hair的有多少个么？这个。。。简单的问题