Will medal...Each of two urns contains green and red balls. Urn I contains 8 green balls and 12 red balls. Urn II contains 5 green balls and 8 red balls. If a ball is drawn from each urn, what is P(red and red)?

Question

anonymous · Answer

first off, why would an urn have a ball in it? that's super disrespectful

anonymous · Answer

I have no idea... it's not me, it's the school XD

anonymous · Answer

Seriously, I need help.. I keep getting the same answer, and it's not one of the answer choices listed.

drbcaptin · Answer

What are your answer choices?

anonymous · Answer

My answer choices are: A. 79/55 B. 24/65 C. 20/33 and D. 2/13

drbcaptin · Answer

I got B. 24/65

anonymous · Answer

Thanks. How did you get that though? I don't understand what I was doing wrong.

drbcaptin · Answer

How did you try and work it out?

anonymous · Answer

I found the probability of them individually, then multiplied the two fractions.

drbcaptin · Answer

Since the trials are independent of each other, meaning whatever you get out of the first urn doesn't change what you can get out of the second urn, there is a nifty formula that we have,
P(AandB)=P(A)∗P(B)
and for your problem, you have that P(A) is the probability of getting a red ball out of the first urn, and the P(B) is the probability that you get a red in the second urn.

anonymous · Answer

Ohhhh okay. Thanks again! I understand c:

drbcaptin · Answer

No problem!!