A boat goes 15 km upstream and 10 1/2 km down stream in 3 hrs 15 min. It goes 12 km upstream and 14 km downstream in 3 hrs. What is the speed of the boat in still water?
A manufacturer faces a -1.2 price elasticity of demand for its product. It is presently selling 7,500 units/day. If it wants to increase quantity sold by 9%, it must lower its price by