What is the common difference of an AP if the first term is 2 and the fifth term is 14 ?

We'll determine the common difference of the arithmetical
progression, writting the general term of the sequence.

an
= a1 + (n-1)*d

a1 is the first term and d is the common
difference

We'll substitute an by a5 and we'll
get:

a5 = a1 + 4d

We'll
substract a1:

a5 - a1 = 4d

d =
(a5 - a1)/4

We'll substitute the given values for a5 and
a1:

d = (14-2)/4

d =
12/4

d = 3

The
common difference of the given arithmetical progression is d =
3.