If we have " n " items and we want to arrange " r " items, the permutation if repetition is allowed =
[tex] n^{r} [/tex]
We have 10 digits, since we are not using 0, then we have 9, n= 9.
Since we want to make 4 digits, so permutation with repetition allowed
= 9⁴ = 6561
We have 26 digits, since we are not using M, then we have 25 left, n= 25.
Since we want to make 2 letters, so permutation with repetition allowed
= 25² = 625
Hence total permutation = 6561 × 625 = 4 100 625
Option C.
But wait a minute!
The question forgot to take note that Alphabets could be capital letters or small letters...
In that case total alphabets of small and big = 2*26 = 52
If we remove the M = 52 - 1 = 51
In this case = 51² = 2601
Total permutations = 6561 × 2601 = 17 065 161
Well you can challenge the question if you want, but if you just ignore this error from the question and be in the mind of the makers of the question, then option C like as we have showed earlier is the answer.
