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.
12 (47) 21
10 (52) 4
64 ? 24

Answer: D. 83

In the first row, 12/421/7 = 3.
In the second row, 10/54/2 = 2.
Clerly, in the third row, we have 64/8 = 24/3 = 8.
So, Missing number = 83.