How many minutes should be spent on Mathematics problems?

Question

There are 200 questions on a 3 hr examination. Among these questions 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?

Answer 1

Since mathematical questions take twice time of the other questions.
50 mathematical questions will be equivalent to 100 other questions .......... (i)

We have 50 mathematical and 150 other questions.
Total time =3 hours = 180 minutes

50 mathematical +150 non mathematical -> 180 minute
100 non mathematical + 150 non mathematical ->180 minute
250 non mathematical ->180 minute
100 non mathematical -> 180×100/250
= 72 minutes
Thus 50 mathematical questions will take total 72 minutes.

Answer 2

Let's time spent on 50 maths problems=x min
then time spent on 50 non maths problems=(x/2)min
and time spent on 150 non maths problems=(3x/2)min
Total time spent=180min
=>x+(3x/2)=180
=>x=72min
so ans:72 minutes spent to solve maths problems.