Number of three digit numbers such that atleast one of the digits is 9 , if repetitions allowed is

How many three digit numbers are there such that atleast one of their digits is 7?

Number of three digit number with atleast one 3 and at least one 2 is

Count the number of three - digit numbers which can be formed from the digits 2,4,6,8, if (i) repetitions of digits is allowed ? (ii) repetitions of digits is not allowed ?

The number of 5 digit numbers having atleast one of their digit repeated is

Find the number of three-digit numbers (repetitions allowed) such that at least one of the digitsis 9