Any term of an AP (except first ) is equal to hal the sum of half sum of terms which arae equidistant from it .

Any term of an AP (except first ) is equal to half the sum of terms which are equidistant from it .

If the first term of an A.P. is 2 and the sum of first five terms is equal to one-fourth of the sum of the next five terms, show that the 20th term is -112.

The sum of the first n terms of an AP whose first term is 8 and the common difference is 20 is equal to the sum of first 2n terms of another AP whose first term is -30 and the common difference is 8 . Find n .

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

If the first term of an A.P. is 2 and the sum of first five terms is equal to one fourth of the sum of the next five terms, find the sum of first 30 terms.

The sum oif the first ten terms of an A.P. is equal to 155, and the sum of the first two terms of a G.P. is 9. Find these progressionsif the first term of the A.P. equals the common ratio of the G.P. and the 1st term of G.P. equals the common difference of A.P.

The first term of an infinite G.P. is 1 any term is equal to the sum of all the succeeding terms. Find the series.

If the sum of p terms of an A.P. is q and the sum of q terms is p, then the sum of p+q terms will be