wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The sum of an infinite number of terms of a G.P. is 20, and the sum of their squares is 100, then the common ratio is

A
25
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
35
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
45
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 35
a+ar+ar2+to =20
a1r=20 ...(1)
a2+a2r2+a2r4+to =100
a21r2=100 ...(2)
Squaring (1), we have
a2(1r)2=400 ...(3)

Dividing (3) by (2), we get
a2(1r)2a21r2=400100
1r2(1r)2=4
1+r1r=4
1+r=44r
5r=3
r=35

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon