Find the sum of 23 terms of the AP 5,9,13,17,…… – InterviewSolution

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1.	Find the sum of 23 terms of the AP 5,9,13,17,……
Answer» Here,a=5,d= (9-5) =4 and n=23 Now,s ` S_(n) = n/2 xx { 2a + ( n-1) xx d}` ` S_(23) = 23/2 xx { 2 xx 5 + ( 23 -1) xx 4}` ` = ( 23/2 xx 98) = 1127` Hence, the sum of 23 terms of the given AP is 1127.

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