Question

Suppose you just received a shipment of ten televisions. two of the televisions are defective. if two televisions are randomly​ selected, compute the probability that both televisions work. what is the probability at least one of the two televisions does not​ work?

Answer 1

Try this solution:

1. for probability of both televisions work:

`P_(2w)=(C^2_8)/(C^2_(10))=(7*8)/(9*10)=0.6(2)`

2. for probability of at least on is defective (it means, the sum = one is defective and two are defective):

`P_(1d)=(C^1_2C^1_8)/(C^2_(10))=(4*8)/(9*10)=0.3(5)` - for P(1defective);

`P_(2d)=(C^2_2)/(C^2_(10))=(2)/(9*10)=0.0(2)` - for P(2defective);

totaly for at least one is defective:

`P_(at \ least \ 1 \ d)=P_(1d)+P_(2d)=(16)/(45) +(1)/(45) =0.3(7)`