Toy probability
A bin contains 25 toys, 5 of which are of good quality ,i.e., they can work infinite times , 10 of the remaining are partially good ,i.e., they will fail to work the 2nd time. Remaining 10 toys are of bad quality which will not work even at the first attempt. A toy is selected at random. What is the probability that the selected toy to continue to work when it is given that the first time it worked perfectly ?
The answer is 0.33333333333333.
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1 solution
It is given that the toy has worked first time, it means that it is either of good quality or of partially good quality.
Thus, no. of toys excluding the bad quality ones are 5+10 = 15.
let E be the event of getting a good quality toy:
P(E)= n ( S ) n ( E )
P(E)= 1 5 5
P(E)= 3 1
Therefore the favorable probability is 0 . 3 3 3 . . . .