
code probability
A security code contains 10 digits. The first 3 come from the letters {A,B,C,D,E,F,G,H,M,P,Q} Letters may repeat once used. The last 7 come from the numbers {0,1,. . .9}. Numbers may NOT repeat once used. How many security codes are possible?
any help would be appreciated. thank you


work needed!!!
can you please explain how you got that for an answer?

First 3 come from letters 26x26x26... (letters may repeated)
The last 7 come from, first 10 numbers (0,1,...,9) and second 9, third 8 etc. because numbers may not repeated.
Therefore, the answer is
26x26x26x10x9x8x7x6x5x4