2.16666... -Meters Per Second
About 4.8467- Miles Per Hour 
About 7.8- Kilometer Per Hour
        
             
        
        
        
Answer:
-30
Step-by-step explanation:
-20-8=-28
-28-12
=-30
 
        
             
        
        
        
1. The total cost for the nails is $12.784 rounded to $12.78. 
2. The total cost of the meal including tip is $49.65.