sandy wrote:

A certain dog kennel houses only collies, labs, and golden retrievers. If the ratio of collies to labs is 5 : 9, there are 66 golden retrievers, and 12 more golden retrievers than labs in the kennel, what percent of the dogs in the kennel are collies?

(A) 5%

(B) 9%

(C) 12%

(D) 20%

(E) 25%

I took 3:34 secs for this question

collies : labs : golden retrievers => c:l:g

Given that c/l = 5x/9x --> eq 1

Given total g = 66 and now question say that golden retrievers are 12 more than labs i.e. l = 54.

From eq 1 , we can take 9x = 54, x = 6

then c = 30.

Now c/c+l+g = 30/150 => 0.2.

D.