This is a non replacement question, so each letter decreases by 1.
No vowels
The question actually starts right here. The preamble tells us that we can only use letters, no numbers, and no symbols. We are not asked to do anything. The first question makes no mention of there being anything special about m. It can be there or it most likely is not. This part of the problem is the first part.
First Part
I'm not going to deal with y. I will declare it to be a consonant.
There are 5 vowels. None of them can be chosen.
21 letters remain (including the m since it has not been limited in any way yet).
21 * 20 * 19 * 18 * 17
================
26 * 25 * 24 * 23 * 22
2441880 / 7893600
0.30934
Note: If your calculator has nPr on it, you can enter 21 nPr 5 to eliminate all the typing.
Second Part
No vowels and the first letter MUST be m
1 * 20 * 19 * 18 * 17/( 26 * 25 * 24 * 23 * 22)
116200/7893600 = 0.01473
Vowels and the first letter m.
1 * 25 * 24 * 23 * 22/ 7893600 = 0.03846
To find the dimensions you can just factor the equation...
x^2+4x-21
x^2-3x+7x-21
x(x-3)+7(x-3)
(x+7)(x-3) and this is equal to LW or WL
And note that x>3 for any possible solution.
Our system is the following :

As you see, the system has only one solution whenever the value of k is. Unlike you have not well written the system.
Bisecting an angle means it divides the angle into two equal parts. If line rs bisects angle qrt which has a measure of 116 degrees, then angle qrs should have an angle of 58 degrees. Hope this answers the question. Have a nice day.
The answer to your question is 15