pushpitkc wrote:

The value of a precious stone is directly proportional to the cube of its weight. If a big stone broke into three parts in the ratio 1:4:5, what was the percentage drop in the value of the stone?

A. 10%

B. 40%

C. 71%

D. 81%

E. 93%

source:

Experts GlobalLet the original weight of the stone be \(10\) units

so original price \(P=10^3k=1000k\), where \(k\) is any constant

as the stone broke in the ratio \(1:4:5\), so the weight of the three stones will be \(1\), \(4\) & \(5\). Revised price will be

\(P_1=1^3k=k\)

\(P_2=4^3k=64k\)

\(P_3=5^3k=125K\)

So Total new price \(= k+64k+125k=190k\)

Hence reduction in price \(= 1000k-190k=810k\)

Reduction % \(= \frac{810k}{1000k}*100=81\)%

Option

D