Hey Jo.

I have same problem with statistics and probability. anyways...

q1) Uses the Multiplication Rule: Consider each number on the plate as a position, or a bin to put a number into. How many numbers can you choose from to put in each position/bin?

I get (10)*(10)*(10)*(10)*(10)

q2)

(a) same again: (10)*(10)*(10)

(b) here the first position must be 5 --> 1 choice

second position can be any of remaining 9 digits --> 9 choices

third position can be any of remaining 8 digits --> 8 choices

Mulitiplication Rule: (1)*(9)*(8) = 72.