Just me chilling in bed

Alicense plate is to consist of 44 digits followed by 55 uppercase letters. determine the number of different license plates possible if the first and second digits must be? odd, and repetition is not permitted.

How do you use the elimination method for this question? explain, because i really want to understand!

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.