There are 200 questions in a 3 hr examination. Among these questions there are 50 mathematics problems. It is suggested that twice as much time be spent on each maths problem as for each other question. How many minutes should be spent on mathematics problems  Choose the correct choice from the following options:
A) 36 minutes  B) 60 minutes  C) 72 minutes  D) 100 minutes  E) None of these
Explanation :   Let x = minutes spent on a non-math problem   then 2x = minutes spent on a math problem   x(200-50) + 2x(50) = 180   x(150) + 2x(50) = 180   150x + 100x = 180   250x = 180   x = 0.72 minutes   Time to spend on math problems:   2x(50)=100x = 100(0.72) = 72 minutes   Answer : 72 minutes
<result>C</result>
There are 200 questions in a 3 hr examination. Among these questions there are 50 mathematics problems. It is suggested that twice as much time be spent on each maths problem as for each other question. How many minutes should be spent on mathematics problems