i'm not sure if i'm doing this question right

Gas cylinder A has a volume of 48.2L and contains N2(g) at 8.35atm at 25 degrees. Gas cylinder B of unknown volume contains He(g) at 9.5atm at 25degrees. When the two cylinders are connected and the gases mixed, the pressure in each cylinder becomes 8.71atm. What is the volume of cylinder B?

 

can i find Vtotal and then subtract the volume of A away from the total to find volume of B, by setting the question up like this:

48.2L/Vtotal= 8.35atm(pressure of A)/17.85atm(pressure of A+B)

 

thanx a bunch