Which of the following will cause an increase in gas pressure in a closed container?
a. reducing the volume
b. adding more gas
c. both b. and c.

C. Both A. and B.

Explanation:

Statement A. Reducing the volume is true because of Boyle's law, which states that for a gas at fixed temperature, the pressure p and the volume V are inversely proportional:

Therefore, when the volume V is reduced, the pressure p increases.

Statement B. Adding more gas is also true: in fact, if we add gas into the container, we will have more molecules of the gas hitting the wall of the container. But the pressure of a gas is exactly given by this: by the collision of the molecules against the wall of the container, so the more the molecules of gas, the greater the pressure.

more than, less

less than, more