Can someone teach me how to do this?

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Acompany had forty one employees and ordered nine hundred eighty uniforms for them. if they wanted to give each employees the same number of uniforms, how many more uniforms should they order so they don't have any extra