There are 16 cups in a gallon, and 7 gallons would be 112 cups since 16 * 7 = 112. If you divide 112 by 2 (2 cups of bird seed each day) then you would get 56 days.
If 2 eggs with bacon cost 2.70, and 1 egg with bacon costs 1.80, that means that 1 egg costs 0.90, so when we subtract once more 0.90 we get the price of the bacon alone, which is in this case 0.90.
