Question

if k/m=m/r=5/4 and if k=6,then what is the possible value of r?
a)6*(5/2)^2     b)6*(4/5)^2       c)1/6*(5/4)^2    d)1/6*(4/5)^2   e) none of these

Answer 1

k/m=m/r
=> k*r= m^2            ...(i)

now,
 k/m=5/4
=> m = 4*k/5  = 4*6 /5

In (i),

r = m^2 / k
r  = (4*6/5)^2 /6