Answer:
Step-by-step explanation:
I may get this wrong because I don't think it's clear enough.
3 Letters
The station call letters must start with 1 of 3 letters
3
The next letter must be one of 25 and the last letter is 24
3 * 25 * 24 = 1800
5 letters
3 * 25 * 24 * 23* 22 = 910800
Total 1800 + 910800 = 912600
(-infinity,3) (3, infinity)
x does not equal 3
