Q13 of 176 Page 21

Mark the correct alternative in each of the following:

If second term of a G.P. is 2 and the sum of its infinite terms is 8, then its first term is


Let the GP be a,ar,ar2


Sum of infinite terms is given by


⇒


⇒


Also according to the question ar =2


∴


Substituting in above equation


⇒


⇒ 8(a-2) =a2


⇒ a2-8a+16 = 0


⇒ (a-4)2 = 0


⇒ a =4.

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