We actually don't need to do any computation. By definition, the inverse function
changes the role of input and output. So, if a function f maps x onto y, the inverse function maps y onto x.
You have to think like this: if the function makes a step further, the inverse function makes that same step back.
This means that the composition
is always the identity function
. In fact,

So, for every function, you have

Answer:
25%
Step-by-step explanation:
Total= 40 students
boys +girls= 40
30 +girls= 40
number of girls
= 40 -30
= 10
Percentage of girls

Alternatively,
percentage of girls
= 100% -(percentage of boys)

No, not reasonable.
98.3 divides by 52.6
Brady used compatible numbers 100 divided by 5 =20
He should've used 100 divided by 50 = 2