Using proportions, it is found that Juan spends 15 minutes on each 5-point problem.
<h3>What is a proportion?</h3>
A proportion is a fraction of a total amount, and is solved using a rule of three.
In this problem, the amount of time is proportional to the amount of points the problem is worth. Hence, for a 5-point problem, in a 75-minute time, the time is given by:
