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An arithmetic series contains 20 numbers. The first number is 102. The last number is 159. Which expression represents the sum of the series?

A.(20 (159-102/2)
B.(20(102+159/2)
C.20(102+159)
D.20(159-102)

2 Answers

2 votes
Answer:
The person above is correct
Step-by-step exp
User Tmarthal
by
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7 votes

Answer:

Option B

Explanation:

we know that

The sum of an arithmetic series is equal to

S=n(a1+an)/2

where

a1 is the first term

an is the last term

n is the number of terms

In this problem we have

n=20

a1=102

an=159

substitute the values in the formula

S=20(102+159)/2