Answer:
0.06x + 0.15y = 69.84
x = (69.84 - 0.15y) / 0.06
y = (69.84 - 0.06x) / 0.15
x + y = 852
((69.84 - 0.15y) / 0.06) + y = 852
y = ?
(I'm not trying to give you the answer but guide you how to do it)
 
        
             
        
        
        
X )0 2 4 y)0 16 32 is ur answer 
        
                    
             
        
        
        
Out of 960 calculators, 8 were found be to defective
Probability:                 

                 0.00833...
As a Percent:
                 0.00833....× 100
                 0.833%
To the nearest tenth of percentage:
                 0.833% ≈ 0.8%
 
        
        
        
Answer is C. Granted gas prices are fixed. if you buy 1 gallon.. price is x. if you buy 2 gallons, price is 2x. and so on. constant rate of change.
        
             
        
        
        
Need more info. What are you trying to look for?