Q13 of 202 Page 10

If S1 is the sum of an arithmetic progression of 'n' odd number of terms and S2 the sum of the terms of the series in odd places, then =

S1 = (2a + (n–1) d)


Out of these odd numbers of terms, there are terms in odd places


S2 = (2a + ( –1) d)


Common difference of two odd places is 2d


S2 = (2a + (n–1) d)


Now,


=


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