Margaret R. answered • 05/09/22
Experienced Algebra, Statistics and Pre-Cal Tutor, HS and College
You will need to compute the probability of getting a brown puppy on first draw, then probability of getting one on the second draw given a brown puppy on the first.
Probability is the number of outcomes that "fit" a category divided by total outcomes.
On the first draw, you have 7 puppies, 3 black and 4 brown. The probability of choosing a brown puppy will therefore be 4/7.
Then, given a brown puppy is taken from the kennel, you need to compute the probability of now selecting another brown puppy. In this case, you now have 6 puppies remaining, 3 black and 3 brown, The probability of choosing a brown puppy on the second draw is 3/6 or 1/2
You would then multiply the result of these 2 probabilities to get the Probability of both events happening (Probability of Brown on 1st x Probability of Brown on second given a brown was selected first)
Margaret R.
This is a sampling without replacement, and multiple events. Probability of brown is 4/7, so IF you replaced and then selected again, it would be 2*(4/7). But since this is without replacement, the probability changes when selecting the second puppy. there are 2 events, so 2 probaility computations regardless.05/09/22