If there are 200 questions in a 3 hr examination. Among these questions are 25 type A problems, which requires twice as much as time be spent than the rest of the type B problems. How many minutes should be spent on type A problems? Choose one
A) 40 min B) 62 min C) 70 min D) 74 min E) 76 min

Rationale: "x = time for type b prolems 2 x = time for type a problem total time = 3 hrs = 180 min 175 x + 25 * 2 x = 180 x = 180 / 225 x = 0.8 time taken for type a problem = 25 * 2 * 0.8 = 40 min answer : a"
Answer: A