For the arithmetic series 1/3+4/3+7/3 + ... determine S7

Question

Jackson Le

Mathematics

24 March, 08:27

For the arithmetic series 1/3+4/3+7/3 + ... determine S7

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Answers (1)

Know the Answer?

Johnathon Floyd · Answer 1

S7 = 70/3

Step-by-step explanation:

Given:

series: 1/3+4/3+7/3 + ...

a = 1/3

Find:

S7

Computation

d = a2-a1

d = 4/3 - 1/3

d = 1

⇒ Sn = n/2[2a + (n-1) d]

⇒ S7 = 7/2[2 (1/3) + (7-1) 1]

⇒ S7 = 7/2[2/3+6]

⇒ S7 = 7/2[20/3]

S7 = 70/3