if 55 percent of a group of people have brown hair and 80 percent of the same group do not have red hair,what fraction of those who do not have brown hair have red hair?A.四分之一B.十一分之四C.九分之四D.九分之五E.五分之四

Question

if 55 percent of a group of people have brown hair and 80 percent of the same group do not have red hair,what fraction of those who do not have brown hair have red hair?
A.四分之一
B.十一分之四
C.九分之四
D.九分之五
E.五分之四

Answer 1

选c吧.题目意思是：有这么一群人,他们中有百分之55的人是棕色头发,有百分之80不是红色头发,请问在那些不是棕色头发的人中红色头发的人占了多少比例.显然人只有一种发色,因此有百分之55是棕色发,百分之二十是红色发,百分之25是其他发色,所以不是棕色发的比例为百分之45,问题答案就是20%/45%即选c.也许这并没有我想得这么简单.