# How many combinations of three digits can be made from the numbers 1 to 10?

9*9*9 = 729 using the digits 1 to 9

and 2*9 using 10 and another digit.

749 in all.

### How many combination of three digits can be made from the number 0-9 that's larger than 15?

We notice that you said "combinations of three digits". You didn't say "3-digit numbers". There are (10 x 10 x 10) = 1000 combinations of three digits. The only combinations of 3 digits that form numbers less than 15 are 000, 001, 002, . . . 012, 013, and 014. There are 15 of those. So the remaining (1000 - 15) = 985 are all larger than 15.

### How many 4 digit combinations can be made from 6 digits?

If the 6 digits can be repeated, there are 1296 different combinations. If you cannot repeat digits in the combination there are 360 different combinations. * * * * * No. That is the number of PERMUTATIONS, not COMBINATIONS. If you have 6 different digits, you can make only 15 4-digit combinations from them.