Because 42 minus 2 is 40 so therefore the answer has to be 40. So what you do is figure out the number that is X to get 40. In that case, it would be 6. 6 times 6 is 36 plus the 4 and you get 40.
22 because 6 inches on top and bottom means you need 12 inchesw each drape and you have 4 drapes so 48 inches therefor rounding that you get 1 yard each added onto the 8 feet and 5 feet for each drape.
