Alex and Chris each need to add a total of 200 liters of water to a swimming pool. Alex adds water to his pool using a container that holds 10 liters of water. Chris adds water to her pool using a container that holds 25 liters of water. X is the amount of water that Alex and Chris still need to add to their pools. Y is the number of times they each fill and empty their container of water. How many more times does Chris need to fill and empty her container to completely fill the pool?
