There are 240 doctors and nurses at a hospital. If the ratio of doctors to nurses is 3 to 7, how many nurses are at the hospital?  Pick one:
A) 168
B) 172
C) 176
D) 180
E) 184

Rationale: "the number of nurses at the hospital is ( 7 / 10 ) * 240 = 168 . the answer is a ."
Answer: A