Answer:
19 11/16 or 315/16
Steps: 
Turn the fractions into an improper fraction and then multiply straight across 
5 1/4 = 21/4 
3 3/4 = 15/4 
(21/4)*(15/4)= 315/16= 19 11/16 
Yes you got it right :)
 
        
                    
             
        
        
        
(10 pounds) - (7 pounds 3 ounces) =
2.8125 pounds
        
             
        
        
        
5.09 times 15 equals 76.35