Question

You have a 3-card deck containing a king, a queen, and a jack. You pick a card, put it back, and pick another. What is the probability that you do not pick the same card twice?

Answer 1

Any ideas on this one?

Answer 2

1/3?

Answer 3

Let's say that the cards have A, B and C on them

A is on the first
B is on the second
C is on the third


If you pick card C and put it back, you'll have a 2 out of 3 chance of NOT picking C again

or

if you pick B, you'll have a 2/3 probability of NOT picking B again

same applies if you pick card A

Answer 4

so you're very close

Answer 5

does that make sense?

Answer 6

so 2/3 becauseif you chose that card once you have a second chance of choosing it again?

Answer 7

it's 2/3 because you're considering the other two remaining cards that aren't the same as the one you're ignoring

Answer 8

oh yeah! that makes since!

Answer 9

you pick A

put it back

now you want either B or C (and NOT A) this next time: so it's 2/3

Answer 10

ok great, glad it does now

Answer 11

thanks!

Answer 12

you're welcome