TS EAMCET 19-July-2022 Shift 1 Solved Paper

In the figure, the chamber A contains a gas, movable chamber B is placed on the top of the gas and it contains n metal balls. The weight of chamber B is supported by the gas. Chamber C has vacuum. Let the gas be in equilibrium at pressure P. Let P′ be the pressure if one of the balls is taken away. Find (P−P′)∕P.