Exchange : 63m = 6300 cm; 56m21cm= 5621cm
So the lengths of the ribbon will be left is : 6300 - 5621 = 679cm = 6.79 m 
Hope it helps! If it is, Brainliest please!
        
             
        
        
        
I got the last answer on the screen.
 
        
             
        
        
        
Answer:
Yes and she would have $2 left over because all the food costs $91.
Step-by-step explanation:
We should set up an equation so that everything makes sense. A calculator would be wise for this problem, but I am going to lay it out anyhow.
We should convert the mixed numbers to improper fractions to not be confused. 3 1/2 becomes 7/2 or 3.5 and 2 1/3 becomes 7/3.
From your wording, we can assume that the money Mrs. Donnelly has is either greater than or equal to $93.
Thus, we have 12*(7/3) + 18*(7/3) is equal to or greater than 93 (this is an inequality).
The math shows that the food costed 91 and so she only has $2 left.