Question

An A.P. consists of 31 terms. If its 16^th term is m, then the sum of all the terms of this A.P. is

विकल्प

• 16 m

• 62 m

• 31 m

• `31/2` m

Answer 1

31 m

Explanation;

Hint:

t₁₆ = m

S₃₁ = `31/2` (2a + 30d)

= `31/2` (2(a + 15d))

...(∵ t₁₆ = a + 15d)

= 31(t₁₆) = 31m