Pipes A, B and C can fill a tank in 30 h, 40 h and 60 h respectively. Pipes A, B and C are opened at 7 a.m., 8 a.m., and 10 a.m. respectively on the same day. When will the tank be full?
A vertical post 15 ft. high is broken at a certain height and its upper part, not completely separated meets the ground at an angle of 30°. Find the height at which the post is broken
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:
Three men do as much work as 4 boys do and the 4 boys can together complete work in 21 days. In how many days will 9 men and 2 boys complete the same work?