math
posted by nurul on .
A game is played by drawing 4 card from an ordinary deck and replacing each card after it is drawn.find the probability that at least 1 king is drawn

When a problem requires "at least one", it is often easier to find the probability of getting none and subtracting the probability from 1 (complement).
Here, probability of not getting a king at a draw is 48/52, or 12/13.
Probability of getting no king at 4 consecutive draws (with replacement) is (12/13)^4.
The complement is 1(12/13)^4, which is the probability of getting at least one king.