According to Boyle’s law, For a fixed amount of an ideal gas kept at a fixed temperature, P (pressure) and V (volume) are inversely proportional.
Therefore,
[tex]P_{1} V_{1} =P_{2} V_{2}[/tex]
Given [tex]P_{1} = 1 atm[/tex] , [tex]V_{1} = 15 \ cubic \ meter[/tex] and [tex]P_{2} = 0.75\ atm[/tex].
Thus,
[tex]V_{2} = \frac{P_{1}\times V_{1} }{ P_{2} } = \frac{1\times 15}{0.75} =20 m^3[/tex]
