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

Question

Mathematics

Guest

23 July, 14:07

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

+4

Answers (1)

Know the Answer?

Felix Cohen · 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