Hello, I got a test coming up, but I don't think I'm getting this correct

If Pressure = Force/Area...

1) Force = 400 lbs Area = 1&1/2 sq in Pressure = ?

Pressure would equal 26.67 PSI?

2) Pressure = 800 PSI Area = 1/2 sq in Force = ?

Force would equal 1600 or 400 lbs?

3) Force = 800 lbs Pressure = 400 PSI Area = ?

Area would equal 2 sq in or 320,000 sq in?

I know this must be very simple but it's the first time I'm doing it.

Thanks for the help