Question

Question #ce627

Answer 1

`2/169` if the order does not matter.

`1/169` if the Jack has to be first, then the `8`

Explanation:

The probability of choosing any particular card from a deck is `1/52`

However, there are `4` jacks and `4` eights in a deck.
`P(J) = P(8)= 4/52`

As it does not specify that the jack has to be first, followed by the eight, we will assume that either order is correct:

Because the first card is replaced, the probability for choosing a card stays the same for the second card.

There are 2 methods to determine this.

`P(J, 8) or P(8,J)`

`=(4/52 xx 4/52) or (4/52 xx 4/52)" "or rarr +`

`=(1/13 xx1/13) + (1/13xx1/13)`

`=1/169+1/169`

`= 2/169`

Or we can consider that the first card can be either a Jack or and eight, then we know what the second card needs to be.

(If the first is an eight, the second must be a jack)

`P(J or 8, "other one") = 8/52 xx 4/52`

`=2/13 xx1/13`

`=2/169`

If the order DOES matter and the Jack has to be first, then:

`P(J,8) = 4/52 xx 4/52 = 16/2704`

`=1/169`