Question

You have three $1 bills, four $5 bills, and two $10 bills in your wallet. You select a bill at random. Without replacing the bill, you choose a second bill at random. Find P($10 then $1).

Answer 1

@estudier help lol

Answer 2

OK, this is more complicated.

First off, how many possibilities (like 6 for a dice)?

Answer 3

looks like 9

Answer 4

That's right.
Now chance of a random draw being a 10?

Answer 5

2/9 ?

Answer 6

Right again.
Now assume you have gotten the 10 and put it in your pocket.
Chance of a 1?

Answer 7

3/9 ?

Answer 8

It is no longer 9, is it?

Answer 9

oh no lol

Answer 10

it's 3/8?

Answer 11

That's right.

Now we want the probability of both events happening one after the other.

So we multiply the probabilities together.

Answer 12

3/9 times 2/9 times 3/8 ?

Answer 13

Think you are mixed up, there are only two probabilities

The ten, 2/9 and
The one, 3/8

Answer 14

oh lol

Answer 15

5/72?

Answer 16

You have added the top and multiplied the bottom....

Answer 17

yes

Answer 18

Um...why?

Answer 19

i messed up? lol

Answer 20

2*3/9*8 = 6/72 = 1/12 or 1 in 12

Answer 21

oh i forgot to simplify lol

Answer 22

Did they give you that as an option?

Answer 23

yes they did :)