can somebody help with this solution
A license plate is to consist of three letters followed by two digits. How many different license plates are possible if the first letter must be a vowel (a,e,i,o,u), and repetition of letters is not permitted, but repetition of digits is permitted?
Let's look at a sample license plate, say, this one
EZI737
We can choose a vowel to go where the E is 5 ways.
We can choose a letter to go where the Z is 25 ways. (We can't use E)
We can choose a letter to go where the I is 24 ways. (We can't use E or Z)
We can choose a digit to go where the first 7 is 10 ways.
We can choose a digit to go where the 3 is 10 ways.
We can choose a digit to go where the last 7 is 10 ways.
So that's (5)(25)(24)(10)(10)(10) = 3000000 possible license plates.
Edwin