Two pipes P and Q can fill an empty tank in 25 hours and 20 hours respectively. Pipe R alone can empty the completely filled tank in 50 hours. Firstly both the pipes P and Q are opened and after 8 hours pipe R is also opened. What will be the total time (in hours) taken to completely fill the tank?
The pie chart shows the number of students enrolled in the various engineering courses that a certain college offers. Study the diagram and answer the following questions.
The measure of the central angle of the sector representing the Electrical course is ________ degrees.