Q.

Total numbers of 3-digit numbers that are divisible by 6 and can be formed by using the digits 1, 2, 3, 4, 5 with repetition, is ________ .         [2023]


Ans.

(16)

Total 3-digit numbers formed by 1, 2, 3, 4, 5 when the last digit in 4 and divisible by 6.

    11→144→114→2!23→2!35→2!]=8

When last digit is 2:

     22→155→113→2!25→2!43→2!]=8

∴Total 3-digit numbers formed by 1, 2, 3, 4, 5 which are divisible by 6 are 16.