Find the sum of each of the following APs:

0.6, 1.7, 2.8, ... to 100 terms.


Here, first term = 0.6

Common difference = 1.7 - 0.6 = 1.1


Sum of first n terms of an AP is


Sn = [2a + (n - 1)d]


S100 = [2(0.6) + (100 - 1)(1.1)]


= (50) × [1.2 + (99 × 1.1) ]


= 50 × [1.2 + 108.9]


= 50 × 110.1


= 5505


Thus, sum of 100 terms of this AP is 5505.


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