how many 3 - digit numbers can be formed from the digits 2 , 3 , 5 , 6 , 7 and 9 , which are divisible by 5 and if the repetition is allowed ?
"since , each desired number is divisible by 5 , so we must have 5 at the unit place . so , the tens place can now be filled by any of the remaining 6 digits ( 2 , 3 , 6 , 7 , 9 , 5 ) therefore the 3 - digit no can be formed by ( 6 * 6 * 1 ) = 36 ways - - - - - - ( since repetition is allowed ) ans - d"
multiply(5, const_4)