A water tank is 2/5 th full. Inlet A can fill the tank in 12 minutes while an outlet pipe B can empty it in 6minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
Suresh goes on a trip on his motor-cycle and rides for 410 kms. If he rides for 5 hours at a speed of 50 km/hr, find at what speed he travels for the remaining 4 hours of the journey?
P, Q and R together can make a table in 40 minutes. P and Q together can make it in 60 minutes. How much time (in minutes) will R alone take to make the table?