A completes 20% of a work in 5 days and B completes one-third of the work in 5 days. They began the work together but B leaves after 3 days. The total number of days needed for completion of the work is:
X, Y and Z can do a piece of work in 46 days, 92 days and 23 days, respectively, X started the work. Y joined him after 2 days. If Z joined them after 8 days from the beginning then for how many days did X work?
A, B, and C can complete a work in 40, 60, and 80 days respectively. They started working together. If A and B left 11 days and 8 days before the completion of work. In how many days they will complete the work.
A tower standing on a horizontal plane subtends a certain angle at a point 160 m apart from the foot of the tower. On advancing 100 m towards it, the tower is found to subtend an angle twice as before. The height of the tower is