It takes 3 pumps 16 hours to empty a tank Meaning it takes 48 hours for one pump by its self So if there are 4 pumps 48/4 it would take them 12 hours They would need to work 12 hours to do it in 1 day
7x-4=52 is correct because he made 7 times more than Jack which is 7x. For example if Jack made 8 decorations, 7 x (8) = 56. If you subtract 4 from 56 you get 52. Therefore, the equation 7x-4=52 is correct.
