Let the first term, common difference and number of terms of an AP are a, d and n, respectively.

Let the no of terms be x

By using the nth term formula i.e. a_n = a + (n - 1)d

a₂₆ = a + 25d = 0 (given)

a = - 25d (eqn 1)

a₁₁ = a + 10d = 3 (given)

- 25d + 10d = 3 (using eqn 1)

- 15d = 3

(eqn 2)

using eqn2 and eqn1 we get

Also,

(given)

hence

Common difference = - 1/5

No of terms = 27