How many 9 digit no are possibly by using the digit 1,2,3,4,5 which are divisible by 4 if repeating is allowed?

First leave out the last two digits, amount of7 digit numbers that are possible by a combination of1,2,3,4,5 with repeating allowed is5^7. Now coming to last two digits divisible by4 in such a combination are just5, namely12,24,32,44,52.

So, the answer is5^8=390625.

• amount of9 digit numbers that are possible by a combination of1,2,3,4,5 with repeating allowed is5^9
• if the number is divisible by4 then it's an even number and the amount of numbers is reduced to2*(5^8)
• not all the even numbers are allowed, only1 number is divisible by four in every10 numbers( remeber that numbers that contain digits over5 are not allowed)
• so I think  the answer is 390625 if I'm not mistaken