Question

20. Three cards are selected form a standard deck of cards and not

Answer 1

We have a probability of  $\frac{13}{52}=\frac{1}{4}$ for the first card to be a diamond. Having drawn this first card without replacement, there are now 12 diamonds remaining in a deck of 51 cards, so the probability that the second card is a diamond, given that the first card was a diamond, is $\frac{12}{51}=\frac{4}{17}.$ Similarly, for the third card, there are 11 diamonds in a deck of 50, so the probability of drawing a third diamond is $\frac{11}{50}.$ Now, since these events are dependent, we multiply these three probabilities to get our answer of $\frac{11}{850}.$