Direct and Inverse Proportions

If a train 120 m long crosses a man in 15 seconds. Then the speed of the train is

A train is running at a speed of 90 km/hr, crosses a pole in 10 seconds. The length of the train is

x and y are in inverse proportion. If y = 15 when x = 3, then the value ofy when x = 9, is

x and y are in direct variation. I f y = 10 when x - 5, then value of y when x = 10, is

If 18 binders bind 900 books in 10 days, then how many binders will be required to bind 660 books in 12 days ?

If ten pipes through which water flows at the same rate can fill a tank in 28 minutes. If three pipes go out of order, how long will the remaining pipes take to fill the tank ?