If there are 200 questions in a 3 hr examination. Among these questions are 10 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 the correct choice from the following answers
A) 17.14286 min  B) 62 min  C) 70.1346 min  D) 74 min  E) 76.1346 min

Rationale: x = time for type b prolems 2 x = time for type a problem total time = 3 hrs = 180 min 190 x + 10 * 2 x = 180 x = 180 / 210 x = 0.72 time taken for type a problem = 10 * 2 * 0.857143 = 17.14286 min answer : a
Answer: A