Question

Find the eleventh term from the last of the AP: 27, 23, 19,....,-65

Answer 1

The 11th from last term is the 11th term of the reverse series, so rewrite in reverse order:

- 65 , ... 19 , 23 , 27

the common difference is 4 (19 - 23)

nth term = a + ( n - 1 )d

so the 11th term

= - 65 + ( 11 - 1 )* 4

= - 65 + 10 Ă— 4 = -65 + 40

= -25

So the 11th from last term is -25