Explanation

We can write this as:

(x/100) × 200 = (y/100) × 250

Simplifying the equation:

2x = 2.5y

Dividing both sides by 2:

x = 1.25y

Now, dividing both sides by y:

x/y = 1.25

x/y = 5/4

So, y:x = 4:5