Question

Two urns contain white balls and yellow balls. The first urn contains 8 white balls and 8 yellow balls and the second urn contains 10 white balls and 3 yellow balls. A ball is drawn at random from each urn.

What is the probability that both balls are white?

Answer 1

@mathmale @e.mccormick

Answer 2

OK, so multiple, independent events. So, do you know what process you use to find multiple independent events? The word multiple is a really good clue.

Answer 3

No I don't.

Answer 4

Well, what math word is close to multiple. You learned it really early on!

Answer 5

Multiply?

Answer 6

Yep! Find each independent event and multiply them.

Answer 7

So if I had 2 decks of cards and I wanted to see if I would get a king out of the first and a heart out of the second it would be:
\(\dfrac{4}{52}\cdot \dfrac{13}{52}\)

Answer 8

Oh that's 52/2704.

Answer 9

I had to refresh the page

Answer 10

You need to simplify:

\(\dfrac{4}{52}\cdot \dfrac{13}{52}=\dfrac{1}{13}\cdot \dfrac{1}{4}=\dfrac{1}{52}\)

Yes, I chose single card and suit because it comes out nice like that.

Do te same sort of thing with your jars.

Answer 11

Ok so I have 1/2 *10/13 = 10/26. Is this correct?

Answer 12

Urns. Whatever.

So individual probabilities get multiplied when doing multiple, independent events. Or for short:

Multiple events means multiply the events!

Simplify yours.

Answer 13

Ok so 5/13?

Answer 14

Yep.

Answer 15

Thank you :)