Question

how many permutations of three different digits(3-digit numbers)are there, chosen from the ten digits 0 to 9 inclusive

Answer 1

Choose three different numbers from 0 to 9.

There are 10 options for the first number. After choosing the first, there are 9 options left for the second number. And after choosing the first two numbers, there are 8 options left for the third number. The total number of combinations is the product of the amount of options for each. Then, the total number of different combinations of 3 different digits is:

`10\cdot9\cdot8=720`