When two fifths of class A is transferred to class B, the number of people in the two classes will be equal?

When two fifths of class A is transferred to class B, the number of people in the two classes will be equal?

There are X students in class A and y students in class B
X-5:2x = y + 5:2x
We can get y = 1 / 5 X
That is, y is one fifth of X