Richard also wants to average 85% on his 6 tests but his tests are all out of 80 points. How many total points does Richard need to earn?

Can someone answer these problems for me

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

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.