The angle of elevation of the top of a tower from the point P and Q at a distance of 'a' and 'b' respectively from the base of the tower and in the same straight line with it are complementary. The height of the tower is:
X can do a work in 3 days, Y does three times the same work in 8 days, and Z does five times the same work in 12 days. If they have to work together for 6 hours in a day, then in how much time can they complete the work?
A vertical pole and a vertical tower are standing on the same level ground. Height of the pole is 10 metres. From the top of the pole the angle of elevation of the top of the tower and angle of depression of the foot of the tower are 60° and 30° respectively. The height of the tower is