Home » Aptitude » Ratio, Proportion » Question
  1. If b is the mean proportional of a and c, then (a – b)3 : (b – c)3 equals
    1. a3 : c3
    2. b2 : c2
    3. a2 : c2
    4. a3 : b3
Correct Option: D

Since b is the mean proportional of a and c.

∴ 
a
=
b
= k (Suppose)
bc

∴  a = bk, b = ck
∴ 
(a − b)3
=
(bk − b)3
(b − c)3(ck − c)3

=
b3(k − 1 )3
=
b3
=
a3
c3(k − 1 )3c3b3



Your comments will be displayed only after manual approval.