Question

Compute the probability that a hand of 13 cards contains all 4 of at least 1 of the 13 denominations.answer: 0.0343

Answer 1

The probability of a hand of 13 cards contains all 4 of one of the denominations, say Aces, is given by:
$\frac{4C4\times48C9}{52C13}=0.00264106$
The same probability applies to getting all 4 of each of the other denominations.
Therefore the required probability is:
$0.00264106\times13=0.0343$
The answer is 0.0343.