If the 6th term of an arithmetic progression is 11 and the first term is 1, find the common difference.

A.
(frac{12}{5}) 
B.
(frac{5}{3}) 
C.
2 
D.
2
Correct Answer: Option D
Explanation
In an AP, Tn = a + (n – 1)d
T_{6} = a + 5d = 11
The first term = a = 1
∴ T_{6} = 1 + 5d = 11
5d = 11 – 1
5d = 10
∴ d = 2