Heat And Thermodynamics

A monoatomic gas at pressure '\(\mathrm{P}\)', having volume '\(\mathrm{V}\)' expands isothermally to a volume '\(2 \mathrm{~V}\)' and then adiabatically to a volume '\(16 \mathrm{~V}\)'. The final pressure of the gas is (Take \(\gamma=5 / 3\) )