Question

The 7th term of an AP is -1 and the 16th term is 17. Find the nth term of it.

Answer 1

7th term ==> a + 6 d= -1

16th term ==> a +  15 d= 17

On eliminating,

- 9d = - 18

=> d = 2

and on substituting in any of the equation;

a + 6(2) = -1

=> a = - 13

therefore

n th term of the given AP is -13 + (n-1)d