In a 3-hr examination of 320 questions, there are 40 mathematics problems. if twice as much time should be allowed for each mathematics problems as for each of the other questions, how many minutes should be spent on mathematics problems?

Total questions = 320

Total mathematics problems = 40

Total non-mathematics problem = 320 - 40 = 280

Twice the amount of time is needed for mathematics problem.

40 x 2x + 280 x = 3 hours

80x + 280x = 3 hours

360x = 180 mins

x = 0.5 mins

2x = 0.5 x 2 = 1 min

Answer: 1 min should be spent on Mathematics problems