Two balls are drawn in succession out of a box containing 5 red and 5 white balls. Find the probability that at least 1 ball was red, given that the first ball was..
A) Replaced before the second draw
B) NOT replaced before the second draw
a) Find the probability that at least 1 ball was red, given that the first ball was replaced before the second draw.

- anonymous

- chestercat

I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!

At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your **free** account and access **expert** answers to this

and **thousands** of other questions

- goformit100

I know the solution...

- anonymous

Can you please help me?

- kropot72

Section A)
Consider the following 3 situations:
(1)
A: First ball red
B: Second ball red
The events A and B are independent therefore
P(two red) = (5/10) * (5/10) ...........................(1)
(2)
A: First ball red
B: Second ball black
The events A and B are independent therefore
P(one red) = (5/10) * (5/10) ...........................(2)
(3)
A: First ball black
B: Second ball red
The events A and B are independent therefore
P(one red) = (5/10) * (5/10) ...........................(3)
The probability that at least 1 ball was red, given that the first ball was replaced before the second draw is the sum of results (1), (2) and (3).
Can you calculate?

Looking for something else?

Not the answer you are looking for? Search for more explanations.

## More answers

- anonymous

Sorry i can not calculate it,

- anonymous

my calculator is currently not working

- anonymous

so this is what it would look like then (5/10)(5/10)+(5/10)(5/10)+(5/10)(5/10)=

- kropot72

You do not need a calculator to work this out:
\[P(at\ least\ one\ red)=(\frac{5}{10}\times \frac{5}{10})+(\frac{5}{10}\times \frac{5}{10})+(\frac{5}{10}\times \frac{5}{10})=?\]

- kropot72

Hint:
\[\frac{5}{10}\times \frac{5}{10}=\frac{1}{2}\times \frac{1}{2}\]

- anonymous

so the answer would be 0.75

- kropot72

Good work! Your answer is correct.

- anonymous

oops no sorry my mistake

- kropot72

0.75 or 3/4 is correct.

- anonymous

How would i find the probability that at least 1 ball was red, given that the first ball s not replaced before the second draw?

- anonymous

take the chance after by subtracting out already drawn balls

- anonymous

hmm?

- kropot72

Section B)
Probability first ball is red = 5/10
Probability second ball is red = 4/9
P(two red) = (5/10 * 4/9) ................(1)
Probability first ball is red = 5/10
Probability second ball is black = 5/9
P(one red) = (5/10 * 5/9) ...............(2)
Probability first ball is black = 5/10
Probability second ball is red = 5/9
P(one red) = (5/10 * 5/9) ...............(3)
\[P(at\ least\ one\ red)=(\frac{1}{2}\times \frac{4}{9})+(\frac{1}{2}\times \frac{5}{9})+(\frac{1}{2}\times \frac{5}{9})=?\]

- anonymous

thank you and the answer i have recieved was 0.77777777777

- anonymous

is that also what you got?

- kropot72

Your answer to B) is correct. Good work :)

- anonymous

thank you for your help! :)

- anonymous

but should i put my answer as 0.78?

- anonymous

it says to simply my answer into a integer or fraction

- anonymous

simplify**

- anonymous

oops nvm its 7/9 hahaha thanks!

- kropot72

To put the answer as a fraction just add the following fractions and simplify:
\[\frac{4}{18}+\frac{5}{18}+\frac{5}{18}=?\]

- kropot72

Yes, 7/9 is correct!

- anonymous

:)

- kropot72

You're welcome :)

Looking for something else?

Not the answer you are looking for? Search for more explanations.