Two cylinder having `m_(1)g` and `m_(2)g` of a gas at pressure `P_(1)` and `P_(2)` respectively are put in cummunication with each other, temperature remaining constant. The common pressure reached will be

Two chambers, one containing m_(1)g of gas at P_(1) pressure and other containing m_(2)g of a gas at P_(2) pressure are put in communication with each other. If temperature remains constant, the common pressure reached will be

Three containes of the same volume contain three different gases. The masses of the molecules are m_(1), m_(2) and m_(3) and the number of molecules in their respective containers are N_(1), N_(2) and N_(3) . The gas pressure in the containers are P_(1), P_(2) and P_(3) respectively. All the gases are now mixed and put in one of the containers. The pressure P of mixture will be