JEE Main · 2005 · 08 May 2005 · Offline · Surface Chemistry

Colloidal particles are far bulkier than the dissolved particles of a true solution. A true-solution particle is smaller than about $1$ nm, whereas a colloidal particle runs from roughly $1$ nm up to $1000$ nm. Translating that length difference into volume, which scales as the cube of the size, puts the ratio $\frac{V_C}{V_S}$ at around $10^3$ or more, so of the estimates offered $\frac{V_C}{V_S}\simeq 10^3$ is the sensible one.