I am kind of stuck on this one
Each of two urns contains green balls and red balls. Urn I contains 10 green balls and 8 red balls. Urn II contains 3 green balls and 10 red balls. If a ball is drawn from each urn, what is P(red and red)?
(a) 23/18
(b) 10/27
(c) 40/117
(d) 18/31
The thing is, I know you may be thinking this is easy but is it 18/31? 18/31 makes sense but doesn't seem as complicated as it needs to be.
P(red&red) = 8/18 * 10/13 = 40/117
why does 18/31 make sense? That would be the probability if all the balls were in a single urn, but you have two separate events from two separate urns.
it is actually c 40/117 i took this test it makes no sense.
To find the probability of drawing a red ball from each urn, you need to consider the number of total possible outcomes and the number of favorable outcomes.
Let's start with Urn I. There are a total of 10 green balls + 8 red balls = 18 balls in this urn. So the probability of drawing a red ball from Urn I is 8/18.
For Urn II, there are 3 green balls + 10 red balls = 13 balls in total. So the probability of drawing a red ball from Urn II is 10/13.
To find the probability of drawing a red ball from both urns, you need to multiply the probabilities together since the events are independent. Therefore,
P(red and red) = P(red from Urn I) * P(red from Urn II)
= (8/18) * (10/13)
To simplify this expression, you can cancel out common factors. Both 8 and 2 can be divided by 2, and 10 can be divided by 2 and 5:
P(red and red) = (4/9) * (5/13)
= 20/117
Therefore, the correct answer is (c) 40/117.
Remember, when calculating probabilities, it's essential to consider all possible outcomes and the number of favorable outcomes.
add 10 + 8=18 then subtract that from all balls :D then it's 18/___(fill in the blank)
if only
i chose the same answer i got thrown off by the and.
its supposed to be then.
not and.
what?