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.
6 11 25
8 6 16
12 5 ?

Answer: B. 16

In the first row, 11 x 2 + 6/2 = 25,
In the second row, 6 x 2 + 8/2 = 16.
.'.  In the third row, missing number = 5 x 2 + 12/2 = 10 + 6 = 16.