What is the probability that one letter and one number appear on a license plate (in any order) if the plate consists of six elements that can be a letter, a number, and can repeat? I am a law student so I really do not possess the skills to approach this problem. This is for a mock trial where an eyewitness remembers seeing a "K" and an "8" on a license plate. This is in Florida where plates have $6$ alpha numeric characters and I would like to know how many plates have those characters out of the set of all possible plates. Any help is greatly appreciated.
The only work I have done on this problem is figuring out how many plates are possible as a permutation $36^6 = 2,176,782,336$.
No idea how to approach the other half of the problem.
The number of plates that don't have a K is $35^6$. The nummber that don't have an 8 is also $35^6$. The number that have neither a K nor an 8 is $34^6$. So the number that do have at least one K and at least one 8 is $$36^6-2\times35^6+34^6$$