Given:- G=2.67, e=0.63

V=1000mL

mloose=1475gm

mcompcat=1770gm

$sd(min)=\frac{1475}{1000}=1.475g/cm^{3}$

$sd(min)=\frac{G.Pw}{1+emax}$, emax=0.81

sd(max)=$\frac{1770}{1000}=1.77g/cm^{3}$

emin=$\frac{G sw}{(sd)}_{max}-1$=0.508

$I_{D}\frac{emax-e}{emax-emin}$

$\frac{0.81-0.63}{0.81-0.508}$

$I_{D}$=0.596

$I_{D}$=59.6%