There are 18 tens in 180 because if you divide 180 divided by 10, you get 18. you can also do it in your head!!! 
Hope this helps!!!
        
             
        
        
        
Ht of ceiling = 10 ft which is two-thirds of living rm ceiling
Ht of living rm ceiling = 2/3x = 10 ft
2/3h = 10 ft
2/3h times 3/2 to solve for h = 10 times 3/2
h = 30/2
h = 15 ft
        
             
        
        
        
The simple formula for velocity is v=d/t.  Velocity equals distance divided by time.  360 miles divided by 180 minutes.  360/180=2.  The car travels at 2 miles per MINUTE.
Now, to change to miles per HOUR.  There are 60 minutes in an hour, so 2*60=120 miles per hour.
Answer: 120 mph