The time t required to drive a fixed distance varies inversely as the speed r. It takes 7hr at a speed of 90km/h to drive a fixed distance. How long will it take to drive the same distance at a speed of 60km/h? It will take ? to drive the same distance at a speed of 60km/h.

The time required for a crew of men to do a job is inversely proportional to the productof the number of men and the number of hours they work per day. If a crew of 15 menworking 5 hrs a day do a job in 10 days, find how long it would take 10 men working 6hours a day to do the job.

A car travelling north at 60 mph and a truck travelling east at 45 mph leave an intersection at the same time. At what rate is the distance between them changing 2 hours later?

When there is no wind, a runner is able to run 10 000 m at an average speed of x m/s. When he runs with a tailwind, his average speed increases by 0.05 m/s and it takes him 15 s less to run the 10 000 m. The equation shown below represents this relationship. 10 000 10 000 x+0.05 X = 15, x > 0 6. When there is no wind, find the runner's average speed, to the nearest hundredth of a metre per second.