Respuesta :
Answer:
Since the events are independent, 30% of his customers have neither a foreign car nor a dog.
Step-by-step explanation:
Let the total number of his customers = 100.
Since the events are independent,
customers with foreign cars + customers that own dogs + customers that have neither a foreign car nor a dog = 100.
But,
Customers with foreign cars = 30% = 30
Customers that own dogs = 40% = 40
Customers with neither foreign car nor dog  = x%
So that,
   30 + 40 + x = 100
    70 + x = 100
   x = 100 - 70
   x = 30
Customers with neither foreign car nor dog  = 30.
Converting this value to percentage,
       =  [tex]\frac{30}{100}[/tex] × 100           Â
       = 30%.
Therefore, 30% of his customers have neither a foreign car nor a dog.