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 and angle twice as before. The height of the tower is

A crate of fruits contains one spoiled fruit for every 25 fruits. 60 % of the spoiled fruit were sold. IF the seller had sold 48 spoiled fruits, then the number of fruits in the crate were:

A tap takes 36 hours extra to fill a tank due to leakage equivalent to half of its inflow. The inflow can fill the tank in how many hours?

In a test consisting of 150 questions carrying 1 mark each, Saurabh answered 80 % of the first 75 question correctly. What percent of the other 75 question does he need to answer correctly to score 60 % overall? 

If cos²α + cos²β = 2, then the value of tan³ α + sin⁵ β is :

The ratio of the cost of table and chair is 9 : 4. The cost of the table is Rs 1250 more than the cost of the chair. What is the cost of the chair?

What will come in place of question mark ( ? ) in the following series?
656, 352, 200, 124, 86, ? 

A moving train crosses a man standing on a platform and a bridge 640 metres long in 15 seconds and 35 seconds respectively. What will be the time taken by the train to cross a platform 1280 meters long?