Question

which letter should be in place of question mark b c d a e c f a ?

Answer 1

Thank you for asking this question from us. If we write the alphabets equivalent to numerical as (A-1, B-2...) then, in a 3*3 matrix we will get
2 3 4
1 5 3
6 1 ?
Now, every row and column adds up to 9 (except the ?). So ? will be replaced by 2 which will make the third row's and column's sum to be 9.
So the answer is B (=2).