A. 9 only bc only 9 can be equal to 9 if it was absolutely value then the answer would be 9 and -9
Given :
Ruth wants to buy a skateboard for $44.
She has $100 in her account. She spent $11.36 to buy stationary.
She also wants to buy some comic books for $3.72 each.
To Find :
The maximum number of comic books, n, that Ruth can buy so that she has enough money left to buy the skateboard.
Solution :
Money left after buying skateboard and stationary is :
Money left = $(100 - 11.36 - 44)
Money left = $44.64
Number of comic she can buy is :

Therefore, she can buy a maximum of 12 books.
Hence, this is the required solution.
Ummm not to freak you out but what’s that in the background?
1/4 squared would be 1/4 times 1/4 which would eqaul 0.063
Again, nice problem. These are not super easy. You need to imagine the triangles in the figure and relate sides.
For instance: ADC, its hypotenuse is 15
For ABC, it is 20,
so 20/15 is the ratio between both triangles. Now let's choose the side with 'x'
x is one side of ADC, the corresponding side in ABC is 15 (the second longest sides). You need to rotate the triangles, etc ... That's the tricky part :)
So:
20/15 =15/x ----> x = 15*15/20 = 225/20 = 45/4
Which is C
Not sure whether it's too late to help you though!!!!
Also notice that it's kind of a product rule:
x * 20 = 15 * 15
I am sure the book explains a short way of getting to this equation, like sides opposite, blah blah, but what i told you is the reason. You asked for understanding it! Best luck!