Holly an her brother Matt were on a raft when they hit a large branch of a tree that was in the water and poked a big hole in it. Water started coming in at a rate of 10 gallons per minutes. Their raft officially sinks with 30 gallons. If Matt is paddling to shore a half-mile away at the rate of 4 miles per hour, what is the minimum rate that Holly must bail out water so that their trip to shore with not include swimming?