A boat covers a distance of 14 km upstream and 16 km downstream in 9 hours. It covers a distance of 12 km upstream and 40 km downstream in 11hours. What is the speed (in km/hr) of the boat in still water?
Marked price of an item is Rs 900. On purchase of 2 items discount is 16%, on purchase of 5 items discount is 44%. Raksha buys 7 items, what is the effective discount?