Let's use Boyle's Law here. P1*V1 = P2*V2
Given: (assuming that there are decimals at the end for Sig Figs)
P1 = 900.mmHg
P2 = 1140.mmHg
V1 = ???
V2 = 250.mL
900.mmHg* ??? = 1140.mmHg * 250.mL
??? = 1.27*250.mL
??? = 318.mL
Therefore, the original volume is 318mL.
