P can complete five-eighths of a work in 15 days and Q can complete three-fourths of the same work in 30 days. They worked together for 8 days and then P left. How much time will Q working alone, take to complete the remaining work?
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?
Two poles of equal height are standing opposite to each other on either side of a road which is 100 m wide. From a point between them on road, angles of elevation of their tops are 30° and 60°. The height of each pole in meter, is: