Question

Show that the progression 13, 20, 27, 34, ......... is an A.P. Write down its (i) first term (ii) common difference (iii) 16th term.

Answer 1

Consecutive differences are equal:

$$20 - 13 = 27 - 20 = 34 - 27 = 7$$

Hence it is an A.P.

Here $$a = 13$$, $$d = 7$$. 

16th term: $$T_{16} = 13 + (16 - 1)\times 7$$

$$= 13 + 105$$

$$= 118$$

So first term = 13, common difference = 7, 16th term = 118.