" 7.Find the sum "3+7+14+24+37+...20" terms."

Find the sum of -7-4-1 + 2…. to 20th term.

If the sum of first 8 terms of an Arithmetic progression is 136 and that of first 15 terms is 465, then find the sum of first 25 terms. OR Ths sum of the 5th and 9th terms of an A.P. is 40 and the sum of the 8th and 14th term is 64. Find the sum of the first 20 terms.

Find the sum of the series 3+7+14+24+37...

The second term of an H.P. is 3/14 and the fifth term is 1/10 . Find the sum of its 6th and the 7th term.

Sum up the following series to n terms : 3+7+ 14+ 24+ 37 + .....

Find the nth term and hence the 20th term of series 2.4+4.6+6.8+…….. Also find the sum of its 20 terms.

Find the nth term and hence the 20th term of series 2.4+4.6+6.8+…….. Also find the sum of its 20 terms.

The third term of an AP is 7 and the 7^(th) term exceeds 3 times the third term by 2. Find the first term and the common difference and the sum of first 20 terms.

In an A.P. the ratio of 7th term to 11th term is 19 : 31 and the sum of these two terms is 20.Find the sum of first twenty terms.