Answer:
For the fifth box, the correct answer is 24.
Since there are 4 different letters, use the formula 1 x 2 x 3 x 4 / {(1) (1) (1) (1)}.
When you solve that, you should get 24/1 or just 24.
Not sure if you have heard of this formula, but it is much more efficient than counting all the possible outcomes.
For the sixth box, the probability of pulling out the letters in the order of MATH is only one of the possible outcomes out of 24.
Thus, the fraction to represent this is 1/24.
Hope this clears up any misunderstandings.