An aquarium tank can hold 6000 liters of water. There are two pipes that can be used to fill the tank. The first pipe alone can fill the tank in 75 minutes. The second pipe can fill the tank in 50 minutes by itself. When both pipes are working together, how long does it take them to fill the tank?

Michelle and julie work at a catering company. they need to bake 264 cookies for a birthday party that starts in a little over an hour and a half. each tube of cookie dough claims to make 36 cookies, but michelle eats about 1/5 of every tube and julie makes cookies that are 1.5 times as large as the recommended cookie size.it takes about 8 minutes to bake a container of cookies, but since julie's cookies are larger, they take 12 minutes to bake. a. how many tubes should each girl plan to bake? how long does each girl use the oven? b. explain your solution process what did you make? c. what assumptions did you make?