Question

he has 72 penciles 96 erasers and he is giving each student the same amount of supplies and there will be nothing left how many students does he have

Answer 1

You need the greatest number of students that divides both totals evenly — the GCD of 72 and 96, which is 24.
So he has 24 students; each would get 72 ÷ 24 = 3 pencils and 96 ÷ 24 = 4 erasers.