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_ _ _ _ _ _ _ _ _ (9 digit number)

Digits that can be used = 1, 2, 3, 4 and 5

For a number to divisible by 4, the last two digits have to be divisible by 4

So, the units digit cannot be 1, 3 or 5

If the units digit is 2, only 12, 32 adn 52 are acceptable as the last two digits

If the units digit is 4, only 24 and 44 are acceptable as the last two digits.

So, total 5 cases 12,24,32,44,52 are possible for the last two digits.

Now, the first 7 digits of the 9 digit number can be filled in 5^{7} ways as each place can be filled by 1, 2, 3, 4 or 5.

So, desired answer = 5^{7}\times 5 = 5^{8}

**Video solution:**

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