Find the sum of n terms of the series . (CBSE 2017)

If the 10th term of an AP is 52 and 17th term is 20 more than its 13th term, find the AP. (CBSE 2017)

How many terms of the A.P.must be taken so that their sum is 636? (CBSE 2017)

The first and the last terms of an A.P. are 8 and 350 respectively. If its common difference in 9, how many terms are there and what is their sum? (CBSE 2011)

How many multiples of 4 lie between 10 and 250? Also find their sum. (CBSE 2011)