Why does the volume of a given mass of gas increase on decreasing its pressure at constant temperature?

Explanation

According to Boyle's PV=constant for a fixed mass of gas at a constant temperature. That is, the product of P and V for a fixed mass of gas at a constant temperature is always constant. Suppose, P and V be the pressure and volume of a given mass of gas at a constant temperature. keeping temperature constant, if the pressure is made to `(P)/(x)` (where `xgt1`), thenthe volume of the gas will be `V xx x` because PV=constant.