You are the teacher is your friend correct?

Yes.

Step-by-step explanation:

Friend's answer is correct.

The probability is 1/9

Step-by-step explanation:

The inner square here is the smaller square

The area of a square is the square of its side length

The area of the small square is 4^2 = 16

The area of the big square is 12^2 = 144

The probability would be the area of the small square divided by that of the entire large square

We have this as;

16/144

= 1/9