Chemistry
posted by Angel .
the pressure in a 10.0 L cylinder is raised from 483 mm Hg to 762 mm Hg. What is the new volume?

p1v1 = p2v2

I don't understand what it is i have to do

It isn't that complicated. I gave you a formula and you are to substitute the numbers into the formula. There will always be one item in the formula not given and you solve for that.
pressure1 x volume 1 = pressure2 x volume2
pressure 1 = 483 mm
volume 1 = 10 L
pressure 2 = 762 mm
volume 2 = unknown
So 483 x 10 = 762 x v2
solve for v2. 
thank you very much

6.34 L