Question 1172933
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Among 10 laptop computers, five are good and five have defects. Unaware of this, a customer buys 6 laptops.
a) What is the probability of exactly 2 defective laptops among them?
b) What is the probability of 3 defective and 3 good laptops among them
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(a)  In this case, the customer gets 2 defective and 6-2 = 4 good laptops.


     The probability to have this selection is  

         P = {{{(C[5]^2*C[5]^4)/C[10]^6}}} = {{{(10*5)/210}}} = {{{5/21}}}.



(a)  In this case, the customer gets 3 defective and 6-3 = 3 good laptops.


     The probability to have this selection is  

         P = {{{(C[5]^3*C[5]^3)/C[10]^6}}} = {{{(10*10)/210}}} = {{{10/21}}}
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