Pipes A and B can fill a tank in 16 hours and 24 hours, respectively and pipe C alone can empty the full tank in x hours. All the pipes were opened together at 10:30 a.m., but C was closed at 2:30 p.m. If the tank was full at 8:30 p.m. on the same day, then what is the value of x?

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

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

A cloth merchant on selling 33 metres of cloths obtains a profit equal to the selling price of 11 metres of cloth. The profit is