Brad says that if a second number is 125% of the first number than the second number must be 75% of the second number is he correct justify your answer

Incorrect.

Step-by-step explanation:

Let, the first number is x, and the second number is y. Given, the second number is 125% of the first number. So, the equation will be

y = 1.25 x

Or, y = 5/4x

Now, multiplying it with 4/5, we get, x = 4/5y

Or, x = 0.80 y

But, Brad is saying the first number must be 75% of the second number. But here we see that the first number is 80% of the second number. That's why Brad is incorrect.