Answer:
If dinner cost 31 British pounds than $38.78 would be the cost in U.S. dollars.
I hope this helps!
 
        
                    
             
        
        
        
Volume of the first dwarf planet (r₁ = 832 mi):

Volume of the second dwarf planet (r₂ = 829 mi):

So difference between the volumes is:

or if we want exact value (we use (a³-b³) = (a-b)(a²+ab+b²) ):
 
 
        
        
        
We know the width of the first picture, is 4
we know the ratio from smaller to larger is 1.5:2
thus     

solve for "w".
we know the length of the first picture, 6

solve for "L".
 
        
        
        
I suppose you're supposed to convert 100111 from base 2 to base 10. We have

so the missing number is 39.