A boat goes downstream in one-third the time it takes to go upstream. Then the ratio between the speed of boat in still water and speed of the stream is

A boat goes 10kms an hour in still water, but takes twice as much time in going the same distance against the current. The speed of the current (in km/hr) is 

Train A takes 1 hour more than train B to travel a distance of 720 km. Due to engine trouble speed of train B falls by one third, so it takes 3 hours more than Train A to complete the same journey. What is the speed of Train A (in km/hr)?

A man can row at 7 km/hour in still water. He finds that it takes twice the time to row upstream than the time to row downstream. The speed of the stream is

B starts 4 minutes after A from the same point, for a place at a distance of 7 miles from the starting point. A on reaching the destination turns back and walks a mile where he meets B. If A's speed is a mile in 8 minutes then B's speed is a mile in ____ minutes.

A shopkeeper sold an item at a profit of 20 %. If he reduces the price of the item by Rs. 900, he incurs a loss of 10 %. What is the cost price of the item?

If the shopkeeper sold the mobile for Rs.15000 and then he gets some loss. If he sold the same mobile at Rs.19200 and then he gets profit is double of loss. Find the cost price of the mobile?

A seller gives 15% discount on an item, if he marked up the price of item 40% above C.P and while selling he cheats the buyer by giving 10% less in weight. Find this overall profit percent (approximately).