Find the sum of last ten terms of the AP 8, 10, 12, …, 126.


First term, a = 8


Common difference, d = 10 - 8 = 2


For finding, the sum of last ten terms, we write the given AP in reverse order.


i.e., 126, 124, 122, …., 12, 10, 8


and First term A = 126 and Common difference D = - 2


Sum of ten terms of new AP is






30
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