## Realated Questions

How many keystrokes are needed to type numbers from 1 to 1000 on a standard keyboard?

How many three digit numbers can be formed using the digits 1,2,3,4,5,6,7 and 8without repeating the digits and such that the tens digit is greater than the hundreds digit and less than the units digit?

How many ways can 4 prizes be given away to 3 boys, if each boy is eligible for all the prizes?