Find the sum of first 10 multiples of 8.

Find the variance of first 10 multiples of 3

Find the sum of first 10 terms of an A.P. 3, 15, 27, 39,…..

Find the sum of the first 8 terms of 3,6,12,24,………

The sum of the third and the seventh terms of an AP is 6 and their product is 8. find the sum of first sixteen terms of the AP.

If the sum of the first 10 terms of an A.P. is 1,200 and First term is 30. Then find the 6^(th) term.

Find the sum of first n terms and the sum of first 5 terms of the geometric series 1+ 2/3 +4/9 +............