Q7 of 176 Page 20

How many terms of the sequence must be taken to make the sum ?

Given:


Sum of GP = 39 + 13√3


∴ Common Ratio = r =


a = √3


To find: Number of terms = n.


Sum of GP for n terms =


⇒


⇒


⇒


⇒ 26√3 = √3(3n - 1)


⇒ 27 = 3n


⇒ n = 3.


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