In an A.P the first term is 2, and the sum of the 1st and the 6th term is 161/2. What is the 4th term
- A.
12 - B.
9^{1}/_{2} - C.
8 - D.
7 - E.
5^{1}/_{2}
Correct Answer: Option B
Explanation
1st term a = 2; 6th term = a + (16-1)d = 2 + 5d
2 + (2 + 5d) = 161/2; 4 + 5d = 161/2
5d = 12.5 ∴ = 2.5
the 4th term is 2 + (4-1)2.5= 91/2