If x is 125% of y, then y is what percent of x?

Let's solve this using algebra.

If x is 125% of y, we can write it as:

x = 1.25y

To find y as a percentage of x, we need to find the value of y in terms of x. Dividing both sides of the equation by 1.25, we get:

y = x/1.25

To express y as a percentage of x, we divide y by x and multiply by 100:

y/x * 100 = (x/1.25) / x * 100 = (x*100) / (1.25*x) = 100/1.25

Therefore, y is 80% of x.