Im having trouble understanding the concept of pressure. Help please!

What is the pressure at the bottom of a tube of mercury that is 0.2 m deep?

An elephant with a mass of 1000 kg stands on a circus platform that weighs 50 kg. The area of the bottom of the platform is 1.25 m². How much pressure is exerted on the floor beneath the platform?

Two barometers are identical except that one is filled with water while the other is filled with benzene. In which barometer will the liquid rise higher, and by how much?

If you increase the pressure on the air inside a cylinder to three times its original value, the volume of the air inside the cylinder will be ____________________.