Question

A 360-mL sample of hydrogen is collected when the pressure is 800 mm Hg. What is the volume that the gas will occupy when the pressure is 720 mm Hg?

360/x=720/800
28800/720=720x/720
400-mL=x

Am I correct?

Answer 1

You're right but the - you have for 400-mL is not needed.