There are 200 doctors and nurses at a hospital. If the ratio of doctors to nurses is 4 to 6, how many nurses are at the hospital? Pick one
A) 110  B) 120  C) 130  D) 140  E) 150

Rationale: "the number of nurses at the hospital is ( 6 / 10 ) * 200 = 120 . the answer is b ."
Answer: B