Tuesday 31 December 2013

SEQUENCE AND SERIES A14

The first term of an AP is 10 and the last term is 80.If the arithmetic progression consists of 30 terms, calculate the sum of all the terms.

Solution

A1 = 10, n=30, An = 80

Sn = n(A1 + An)
       2

S30 = 30(10 + 80)
         2

S30 = 15 x 90

S30 = 1350


Hence the sum of all 30 terms is 1350.

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