How many natural numbers are their from 1 to 1000 which have none of their digits repeated.

How many natural numbers are their from 1to 1000 which have none of their digits repeated.

(i) How many three - digit numbers are there, with no digit repeated ? (ii) How many four - digit numbers are there, with no digit repeated ? (iii) How many natural numbers from 1 to 1000 have none of their digits repeated ?

How many numbers are there between 100 and 1000 which have exactly one of their digits as 7?

How many numbers are there between 100 and 1000, which have exactly one of their digits as 7?

(i) How many numbers are there between 100 and 1000 such that at least one of their digits is 7 ? (ii) How many of them have exactly one of their digits as 7 ?

How many numbers are there between 100 and 1000 such that at least one of their digits is 7?

How many numbers are there between 100 and 1000 in which all the digits are distinct?

How many numbers are there between 100 and 1000 in which all the digits are distinct?