Question
Download Solution PDFSum of first 25 terms in the following series would be
7, 11, 15, 19, 23, …Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
series = 7, 11, 15, 19, 23, …
Formula Used:
Sn = n / 2 × {2a + (n - 1) × d}; where n= number of terms, d = common difference, a = first term, Sn = sum of n terms; d = (a2 - a1); a2 = second term of A.P., a1 = first term of an A.P
Calculation:
Using the above formulae, we get d = 4
⇒ S25 = 25 / 2 × {2 × 7 + (25 - 1) × 4}
⇒ S25 = 55 × 25
⇒ S25 = 1375
Required sum of 25 terms = 1375
Therefore the correct answer is 1375.
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