Write down any three-digit number (for example, 425). Examine why they work ?
Make a six-digit number by repeating these digits in the same order (425425). Your new number is divisible by 7, 11, and 13.

How many three-digit numbers are divisible by 7?

Find the sum of all three-digit natural numbers, which are divisible by 7.

How many six-digit numbers are there in which no digit is repeated, even digits appear at even places, odd digits appear at odd places and the number is divisible by 4 ? (a) 3600 (b) 2700 (c) 2160 (d) 1440

A five digit number of formed by writing the digits 1, 2, 3, 4, 5 in a random order without repeatation. Then the probability that the number is divisible by 4, is -

How many 6-digit numbers can be formed from the digits 0, 1, 3, 5, 7 and 9 which are divisible by 10 and no digit is repeated ?

How many four-digit numbers can be formed by using the digits 1, 2, 3, 4, 5, 6, 7 if at least one digit is repeated.

How many numbers of 5 digits can be made with the digits 0,1,2,3,4,5 which are divisible by 3, digits being unrepeated in the same number ? How many of these will be divisible by 6 ?

Find the number of three-digit numbers from 100 to 999 including all numbers which have any one digit that is the average of the other two.

find the number of positive number with three digits divisible dy 5 such that the digits in each number in each number are different