SSC Government Jobs Exams Logical Reasoning Number Series

The 5th, 8th and 11th terms of a G.P. are a, b, c
respectively, then which one of the following is
true -
(A) 2b = ac (B) b2
= ac
(C) a + b + c = 0 (D) None of these

Read Solution (Total 2)

let x=1st term and r= c.r
so a=x*r^4, b=x*r^7, c=x*r^10
b^2=x^2*r^14
and a*c=x^2*r^14
so b^2=ac
11 years agoHelpfull: Yes(0) No(0)

B b^2 =ac
b/a = c/b
Hence b^2 =ac
10 years agoHelpfull: Yes(0) No(0)

SSC Other Question

The diameter of a right circular cone is increased
by 10% and its height is decreased by 10%. The
percentage increase in its volume is-
(A) 3.9% (B) 5.9%
(C) 8.9% (D) 10% A car travels three-fourth of the distance at the
speed of 25 kmph and the remaining distance at
the speed of 10 kmph. What is the average speed
of the car for entire journey ?
(A) 12.5 kmph
(B) 21.25 kmph
(C) 17.75 kmph
(D) None of these