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 4 5
3 7 12
3 ? 22

Answer: B. 10

We have : 3 + 4 = number below 4 = 7;
3 + 4 + 5 = number below 5 = 12.
3 + 7 + 12 = number below 12 = 22.
.'. Missing number = 3 + 7 = 10.