Correct Answer - 2.22
`P_(1) = 5` `P_(2)=1`
`v_(1)=1` `v_(2)=3`
` T_(1) = 400` `T_(2)= 300`
`n_(1)= (5)/(400R) ` `n_(2)=(3)/(300R)`
Let volume be `(v+x) v= (3-x) 15-5x= 4+4x`
`(P_(A))/(T_(A))=(P_(B))/(T_(B))`
`implies (n_(b_(1))xxR)/(v_(b_(1)))=(n_(b_(2))xxR)/(v_(b_(2)))`
`implies (5)/(400(4+x))=(3)/(300R(3-x))`
`implies 5(3-x) = 4+4x`
`implies x= (11)/(9)`
`v= 1+x=1+(11)/(9) = ((20)/(9))=2.22`