An A.P. consists of 31 terms. If its 16th terms is m, then the sum of all the terms of this A.P. is

An A.P. has 21 terms. If its 11^(th) term is 25, sum of all the term is :

An A.P. consists of n ( odd terms ) and its middle term is m. Then the sum of the A.P. is :

An A.P. consists of n terms. If the sum of its first three terms is x and the sum of the last three terms is y, then show that, the sum of all the terms of the A.P. is (n)/(6)(x+y) .

An A.P. consists of 57 terms of which 7th term is 13 and the last term is 108. Find the 45th term of this A.P.

If 11th term of A.P. is 38 and 16th term is 73, then its first term is :

If an A.P. consists of n terms with first term a and n^(th) term l then show that the sum of the m^(th) term from the beginning and the m^(th) term from the end is (a+l) .

The sum of the 2nd term and the 7th term of an A.P. is 30. If its 15th term is 1 less than twice of its 8th term, find the A.P.

The first term of an A.P. is 20 and the sum of its first seven terms is 2100, find the 31st term of this A.P.