An observer on the top of a tree finds the angle of depression of a car moving towards the tree to be 30 degrees. After 3 minutes, this angle becomes 60 degrees. After how much more time will the car reach the tree?
Pipe A and Pipe B can alone fill a tank in 20 hours and 30 hours, respectively and Pipe C alone can empty the tank in 15 hours. If pipe A opened alone for the first hour and Pipe B opened alone for the second hour and after the second hour all three pipes are opened, then the total time required to fill the tank is –
A, B and C can individually complete a task in 24 days, 20 days and 18 days, respectively. B and C start the task, and they work for 6 days and leave. The number of days required by A alone to finish the remaining task is: