88=4*22=> sqrt88=2sqrt22
sqrt22 is approximately sqrt25=5
so 4 < sqrt22 < 5
8 < 2sqrt22 < 10
8 < sqrt88 < 10
        
             
        
        
        
we know that the multiplication comes first in the family then we start from left to right
4 x 5= 20
9-20 = -11
-11 + 6 = -5
there you go!
 
        
                    
             
        
        
        
The price is 36 because 40% of 65 is 29 and 65-29 equals 36.