By how much will the mean free path of a gas molecule is a vessel at constant `P` change if the temperature is reduced by `20%`?

Options

A. `12.5%` decrease
B. `12.5%` increase
C. `80%` decrease
D. `80%` increase

Explanation

`lambda prop (T)/(P)`, i.e., `(lambda_(1))/(T_(1))=(lambda_(2))/(T_(2))` (at constant pressure)
If temperature is reduced, `lambda` will decrease.
`(lambda_(2))/(lambda_(1))=(T_(2))/(T_(1))=(0.8T_(1))/(T_(1))=0.8` i.e., `80%` decrease