Question

There are certain benches in a classroom. If 4 students sit on each bench, 3 benches are left vacant; and if 3 students sit on each bench, 3 students are left standing. What is the total number of students in the class?

Answer 1

Let the number of benches in the class = x

Number of students sitting in one bench = 4
Number of benches left = 3
Total number of students = 4(x - 3)

Number of students sitting in one bench = 3
Number of students left = 3
Total number of students = 3x + 3

Since the total number of students is the same,
so 4(x - 3) = 3x + 3
⇒ 4x - 12 = 3x + 3
⇒ x = 15
Therefore, the number of benches = 15
Number of students
= 4(x - 3)
= 4(15 - 3)
= 4(12)
= 48.