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A geometrical progression of positive terms and an arithmetical progression have the same first term. The sum of their first terms is 1 , the sum of their second terms is (1)/(2) and the sum of their third terms is 2. Calculate the sum of their fourth terms.

The sum of the first five terms of an AP and the sum of the first seven terms of the same AP is 167. If the sum first ten terms of this AP is 235, find the sum of its first twenty terms.

The sum of the first five terms of an AP and the sum of the first seven terms of the same AP is 167. If the sum first ten terms of this AP is 235, find the sum of its first twenty terms.

If the sum of first m terms of an A.P.is the same as the sum of its first n terms,show that the sum of tis (m+n) terms is zero.

The sum of first three terms of a G.P. is 15 and sum of next three terms is 120. Find the sum of first n terms.

If the sum of the first four terms of an AP is 40 and the sum of the first fourteen terms of an AP is 280. Find the sum of first n terms of the A.P.

The sum of the first five terms of an A.P. and the sum of the first seven terms of the same A.P. is 167. If the sum of first 10 terms of this A.P. is 235, find the sum of its first twenty terms.

If the sum of first m terms of an A.P. is the same as the sum of its first n terms, show that the sum of tis (m+n) terms is zero.