by default is without replacement

4 votes

A batch of one hundred bulbs is inspected by testing four randomly chosen bulbs. The batch is rejected if even one of the bulbs is defective. A batch typically has five defective bulbs. The probability that the current batch is accepted is__________.

8 votes

Best answer

3

Hi @rajan,

Actually we are choosing in one go ->

So P(Selecting 4 working bulbs) = $\frac{\binom{95}{4}}{\binom{100}{4}}$