Does anyone know what the slope should be

What is best way to getting answer for my exam is

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Acontainer full of water weighs 15.5 lbs. when ¼ of the water is poured out, the container now weighs 12 ½ lbs. how much does the container weigh when empty?