Answer:
 The probability that exactly one switch is good is

Step-by-step explanation:
The probability that a switch is defective is:

The probability that a switch is not defective is

Therefore, if two switches are selected, the probability that exactly 1 is good is:



 
        
                    
             
        
        
        
-4/3 -5/1= 120 so if you add them they equal 120 which is -120
        
             
        
        
        
Answer:
a
Step-by-step explanation:
it won't be 5
nor 60
and it won't be 15
 
        
             
        
        
        
I think its 6 i'm not sure hope this might help