I’m not exactly sure, but I think you have to find the percentage of the people in the math tutoring compared to the total. You can do this by finding the total number of people, which would be 200, and then dividing 40 by 200, to get 20%, so 20% of the total students participated in the math tutoring. So, using this logic, 20% of 100 is 20, so 20 students would go to math tutoring if there was a total of 100 students