Number of students in Math136 = 480
We are given that the number of students in Math136 is 20% more than the number of students in Math123. Let the number of students in Math123 be x. So we can set up the equation as:
Number of students in Math136 = 20% more than number of students in Math123
Number of students in Math136 = 20% more than x
480 = 20% more than x
480 = 20% of x + x
480 = 0.20x + x
480 = 1.20(x)
x = 480/1.20 = 400
This means, there are 400 students in Math123.
