A ship is 40 km away from shore. There is a hole in the ship from which \(\frac{{15}}{4}\) tons of water come in the ship in every 12 mins. There is another outlet tap that throws out 12 tons of water every hour. Find at what speed it should move such that when it begins to sink a rescue ship moves with 2 km/hr escapes the passengers of the ship if 60ton of water is enough to sink?