Q22 of 46 Page 1

Find the 60th term of the AP 8, 10, 12, …., if it has a total of 60 terms and hence find the sum of its last 10 terms.

First term, a = 8


Common difference, d = 10 - 8 = 2


Using the nth term formula, i.e. an = a + (n - 1)d


a60 = a + 59d = 8 + 59(2) = 118 + 8 = 126


Sum of last 10 terms = Sum of 60 terms - sum of 50 terms


Let sum of last term be S


Using sum of first n terms of an AP formula i.e.





S = 30(16 + 118) - 25(16 + 98)


S = 30(134) - 25(114) = 1170


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