Q3 of 85 Page 104

For a given A.P. with

S10 = 50, a = 0.5, find d.

Formula used.


Sn = [2a + (n–1)d]


⇒ S10 = 50


⇒ n = 10


⇒ a = 0.5S10 = [2×0.5 + (10–1)d]


50 = 5[1 + 9d]


= 1 + 9d


9d = 10–1


d = = 1


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