The time taken by a boat to go a certain distance upstream is twice the time taken by it to go the same distance downstream. If the speed of the stream is 3 km/h, then how much time (in hours) will the boat take to go 52 km upstream?
A pump can fill a tank with water in 1 hour. Because of a leak, it took \(1{1\over3}\) hours to fill the tank. In how many hours can the leak alone drain all the water of the tank when it is full?
Pipes A, B and C can fill a tank in 15, 30 and 40 hours, respectively. Pipes A, B and C are opened at 6 a.m., 8 a.m. and 10 a.m., respectively, on the same day. When will the tank be full?
A can do one-third of a work in 15 days, B can do 75% of the same work in 18 days and C can do the same work in 36 days. B and C work together for 8 days. In how many days will A alone complete the remaining work?