Let the sum of an infinite G.P., whose first term is a and the common ratio is , be 5 . Let the sum of its first five terms be . Then the sum of the first 21 terms of an A.P., whose first term is term...

Let the sum of an infinite G.P., whose first term is a and the common ratio is r, be 5 . Let the sum of its first five terms be 98/25. Then the sum of the first 21 terms of an A.P., whose first term is 10ar,n^{{th}{~}} term is a_{n} and the common difference is 10ar^{2}, is equal to\: Sequence & Series (Mathematics)

Let the sum of an infinite G.P., whose first term is a and the common ratio is

r

, be 5 . Let the sum of its first five terms be

98/25

. Then the sum of the first 21 terms of an A.P., whose first term is

10ar,n^{\text{th}\text{~}}

term is

a_{n}

and the common difference is

10ar^{2}

, is equal to