[" 7.Obtain the sum of the first "56" terms of an "],[" A.P.whose "19^(" th ")" and "38^(" th ")" terms are "52" and "],[148" respectively."]

Obtain the sum of the first 56 terms of an A.P. whose 19th and 38th terms are 52 and 148 respectively.

Obtain the sum of 56 terms of an A.P. whose 19^(th) and 28^(th) terms are 52 and 148 respectively.

Obtain the sum of the first 56 terms of an A.P. Whose 18th and 39th terms are 52 and 148 respectively. (1) Usint t_(18) and t_(39) find two simultaneous equations in variables a and d. (2) Using these equations, find S_(56)

Obtain the sum of 56 terms of an A.P whose 19th and 38th term are 52 and 148 respectively.

If the sum of the first 14 terms of an A.P is 1050 and its first term is 10 , find the 56^(th) term .

The sum of the first 4 terms of a G.P. is 40 and the sum of first 8 terms is 3280. Obtain the G.P.

The sum of first 5 terms and first 15 terms of an A.P. are equal. Find the sum of its first 20 terms.

The sum of first 5 terms and first 15 terms of an A.P. are equal. Find the sum of its first 20 terms.