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.
3 2 2
6 20 4
12 25 64
6 10 ?

Answer: B. 8

In the first column, 3√3 x 6 x 12 = 3√216 = 6.
In the second column, 3√2 x 20 x 25 = 3√1000 = 10.
.'. In the third column, missing number = 3√2 x 4 x 64 = 3√512 = 8.