Two identical vessels A and B with frictionless pistons contains the same ideal gas at the same temperature and the same volume V. The masses of gas in A and B and $m_A$ and $m_B$ respectively. The gases are allowed to expand isothermally to the same final volume 2V. The change in pressures of the gas in A and B are found to be $\Delta P$ and $1.5 \Delta\;P$respectively. Then: