Question

The first two terms of a geometric progression add up to 12. The sum o
terms is 48. If the terms of the geometric progression are alternately po
the first term is
(a)-4
(6)-12
(c) 12
(d) 4​
what is correct option

Answer 1

Answer:

I thik so that the correct anser is -12

Answer 2

Answer:

Let G.P., a, ar, ar²,ar³

Given a+ar=12... (i)

and ar²+ar³=48=r²

(a+ar)=48.

⇒r^2(12)=48 using(i)

⇒r^2=4=r=±2

Vibhor Jindal....

but r=2 is rejected(sign of GP is

alternatively positive and negative, so ratio is negative)

So,r=−2

a+ar=12⇒a(1−2)=12⇒−a=12

∴r=−2⇒a=−12