A standard deck of cards has 52 cards. You choose one card from the deck. Let event A be you choose a black card and event B be you choose a king. Find P(A)⋅P(B) , P(A and B) , and determine whether events A and B are independent.

Enter the first two answers in fraction form.

(2 points)
P(A)⋅P(B)=
;
P(A and B)=
;
Enter 1 if events A and B are dependent. Enter 2 if events A and B are independent

1 answer

To solve for the probabilities \( P(A) \) and \( P(B) \), and determine the independence of the events, we start with identifying the events and their outcomes in a standard deck of 52 cards.

Event A: You choose a black card.
There are 26 black cards in a standard deck (13 spades + 13 clubs).
Thus, the probability of selecting a black card is: \[ P(A) = \frac{26}{52} = \frac{1}{2} \]

Event B: You choose a king.
There are 4 kings in the deck (one in each suit).
Thus, the probability of selecting a king is: \[ P(B) = \frac{4}{52} = \frac{1}{13} \]

Now we can calculate \( P(A) \cdot P(B) \): \[ P(A) \cdot P(B) = \left(\frac{1}{2}\right) \cdot \left(\frac{1}{13}\right) = \frac{1}{26} \]

Next, we find \( P(A \text{ and } B) \), which represents the probability of selecting a card that is both black and a king.
There are 2 black kings (King of Spades and King of Clubs) in the deck.
Thus, \[ P(A \text{ and } B) = \frac{2}{52} = \frac{1}{26} \]

Now we check if events A and B are independent. Two events A and B are independent if: \[ P(A \text{ and } B) = P(A) \cdot P(B) \]

We already have:

  • \( P(A) \cdot P(B) = \frac{1}{26} \)
  • \( P(A \text{ and } B) = \frac{1}{26} \)

Since \( P(A \text{ and } B) = P(A) \cdot P(B) \), the events A and B are independent.

Putting it all together, we have:

\[ P(A) \cdot P(B) = \frac{1}{26} \] \[ P(A \text{ and } B) = \frac{1}{26} \] Events A and B are independent, so we enter 2 as our final answer.

Thus, the final answers are:

  • \( P(A) \cdot P(B) = \frac{1}{26} \)
  • \( P(A \text{ and } B) = \frac{1}{26} \)
  • Events A and B are independent: 2