Of the 3-digit numbers using the digits 1 to 9 allowing repeats, I pick one at random; determine the probability that my number is 350

Question

I got 7 x 5 x 9/ 9^3 -1/ 9^3 = 34/81 and the teacher said this was wrong. Could someone tell me what the answer is and how they go to it?

Kenneth S. · Accepted Answer

how many 3-digit numbers exceed 350?   999-350 = 649.
 
how many 3-digit numbers are there?   999 - 99 = 900.

Of the 3-digit numbers using the digits 1 to 9 allowing repeats, I pick one at random; determine the probability that my number is > 350