24 red marbles is 40% of how many marbles

60 marbles

Step-by-step explanation:

Given:  24 red marbles is 40% of how many marbles

Let number of marbles be x

"24 red marbles is 40% of how many marbles"

             24 = 40% of x

solve for x

First change % to decimal

    24 = 0.40x

Division property of equality, divide by 0.04 both sides

     x = 24÷0.40

     x = 60

Hence, 40% of 60 is 24