In the following question, a matrix of certain characters is given. These characters follow a certain trend, row-wise or column-wise. Find out this trend and choose the missing character accordingly.
H K Q
C G O
E J ?

Answer: A. T

Putting A = 1, B = 2, ..., Z = 26, we get the given matrix as

8 11 17
3 7 15
5 10 ?

Clearly, 2 x (2nd column - 1st column) = 3rd column - 2nd column.
Let the missing letter be the nth letter of the alphabet.
Then, 2 x (10 - 5) = n - 10 or n - 10 = 10 or n = 20.
So, the missing letter is the 20th letter, which is T.