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Find the sum of the first 20 terms of an arithmetic series if the first term is 4 and the common difference is 3.

User Stb
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The sum of first 20 terms of Arithmetic Series is 650 if the first term is 4 and the common difference is 3.

Explanation:

First Term (a) = 4

Common difference (d) = 3

The number of term (n) = 20

The sum of an Arithmetic series of (n) number of terms, with first term (a) and the common difference (d) is equal to

Sum = (n/2) * ( 2 * a + (n -1) * d)

So putting the values of a,d, n

Sum = ( 20/2) * ( 2 * 4 + (20 -1) *3 )

Sum = (10) * ( 8 + 19 * 3)

Sum = 10 * ( 8 + 57)

Sum = 10 * 65 = 650

Hence the sum of first 20 terms of Arithmetic Series is 650 if the first term is 4 and the common difference is 3.

User Xiaoyu Yu
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