Mathematics

In an A.P the first term is 2, and the sum of the 1st and the…

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.
    91/2
  • C.
    8
  • D.
    7
  • E.
    51/2
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