In order to find the answer for this question we can use Boyle's law, which tells us that the same amount of volume times pressure in one situation must be equal to the amount of volume times pressure in a second situation, the formula is:
P1 * V1 = P2 * V2, in our question we already have P1, V1 and V2
I will use atm instead of torr to make the calculations easier, and when we get the final value I will use torr
0.82atm * 303.4mL = P2 * 835mL
248.78 = 835P2
P2 = 0.29atm or 220.4 torr
The pressure, when we have 835mL, will be 0.29 atm or 220.4 torr