Question

In a school cafeteria, 40% of the students buy lunch. of those students, 15% also bring food from home. if 3 students buy lunch and bring food from home, how many students are in the cafeteria?

Answer 1

By reversing the given percentages, we can calculate that there are 50 students in total in the cafeteria.

Step-by-step explanation:

The question involves calculating the total number of students in a cafeteria based on given percentages and a known quantity of students who both buy lunch and bring food from home. To find this number, we need to use reverse percentages. We are told that 15% of the students who buy lunch also bring food from home, and that there are 3 such students. If these 3 students represent 15% of the students who buy lunch, we can find the total number of students who buy lunch by dividing 3 by 15% (or 0.15). Subsequently, since 40% of the students in the cafeteria buy lunch, we can determine the total number of students in the cafeteria by dividing the number of students who buy lunch by 40% (or 0.40).

First, calculate the number of students who buy lunch:

Number of students who buy lunch = 3 ÷ 0.15

= 20 students.

Next, calculate the total number of students in the cafeteria:

Total number of students in the cafeteria = 20 ÷ 0.40

= 50 students.