The distance around the tire of a motorized scooter is 21.98 inches. the tires make one revolution every 1/10 second find the speed of the scooter in miles per hour. round to the nearest tenth

In order to do conversion on these types of problems. 
1.You first have to determine the relationship and the current unit and the target unit which it will be converted into. 
2.In this case feet to meters and seconds to minutes 
3.Determine the conversion rate: 1 hr = 60 min = 60 seconds 1hr = 3600 sec; 
4.Next, is the time which is 2.198 in/hr x 3600 sec / 1hr = 0.1 mi/hr