If it alternates and you start with a letter, then there are 11,232,000 permutations. Then if you start with a number and alternate, there are another 11,232,000 permutations, for a total of 22,464,000 permutations.
If you exclude the letters I, S, B, and O (because they look kind-of like 1, 5, 8, & 0 - kind-of important on license plates) then you are down to 6,652,800 & 13,305,600 respectively.
It is 720.
Only 5 ways: one each with one of the letters missing.
The largest 4 digit number with repetition is 9999. The smallest 3 digit number without repetition is 102 9999 - 102 = 9897
Largest 4 digit number with repetition is 9999 Largest 3 digit number without repetition is 987 Difference is 9999 - 987 = 9012.
9876-102 9704
uncopyrightable
It is 720.
This is known as internal rhyme. Internal rhyme occurs when words within the same line or within nearby lines of poetry have the same vowel sounds but different consonant sounds. It can add musicality and emphasis to the language.
9999
8889
9774
9876 - 123= 9753
Only 5 ways: one each with one of the letters missing.
The largest 4 digit number with repetition is 9999. The smallest 3 digit number without repetition is 102 9999 - 102 = 9897
Largest 4 digit number with repetition is 9999 Largest 3 digit number without repetition is 987 Difference is 9999 - 987 = 9012.
9876-102 9704
8888