In a tree, 3/7 of the birds are robins while the rest are bluejays. If 1/3 of the robins are female and 3/5 of the bluejays are female, what fraction of the birds in the tree are male?
Choose the correct choice from the following answers.
A) 11/35	B) 14/35	C) 18/35	D) 31/70	E) 37/70
The fraction of birds that are male robins is (2/3)(3/7)=2/7.   The fraction of birds that are male bluejays is (2/5)(4/7)=8/35.   The total fraction of male birds is 2/7 + 8/35 = 18/35.   The answer is 18/35.
<result>C</result>
In a tree, 3/7 of the birds are robins while the rest are bluejays. If 1/3 of the robins are female and 3/5 of the bluejays are female, what fraction of the birds in the tree are male?