Thread: At least 1.

Hello
I'm trying to understand an example given in a book I have. The book is The Theory of Gambling and Statistical Logic, R Epstein, page 16.

"The probability of drawing at least one king in two tries from a deck of 52 cards is 396/(52*51) = 0.149 ."

I know I can solve this question by finding the probability of no king and subtracting from one.
1 - (48/52 * 47/51) = 0.149

In the first example I don't understand where 396 comes from. If I was working from the beginning , how would I get to 396?

phil

Originally Posted by phil_b

Hello
I'm trying to understand an example given in a book I have. The book is The Theory of Gambling and Statistical Logic, R Epstein, page 16.

"The probability of drawing at least one king in two tries from a deck of 52 cards is 396/(52*51) = 0.149 ."

I know I can solve this question by finding the probability of no king and subtracting from one.
1 - (48/52 * 47/51) = 0.149

In the first example I don't understand where 396 comes from. If I was working from the beginning , how would I get to 396?

phil

Draw a tree diagram. Then you will understand where the following comes from:

(4)(3) + (4)(48) + (48)(4) = 396.

Thank you Mr fantastic.
I must start using tree diagrams more.