Question

http://prntscr.com/9ib0c9
http://prntscr.com/9ib0ej

Answer 1

Are my answers correct?

Answer 2

As always one step at a time. Lets look at the first one how many marbles in total?

Answer 3

10

Answer 4

Good ignoring the do not replace part, what is the probability of picking 4 green marbles?

Answer 5

4/10

Answer 6

Great!

Now it says do not replace it, which means we pick it up and don't put it back into the bag, so lets just say we tossed it away. Now how many marbles are there in the bag?

Answer 7

would i do 4/10 * 3/9

Answer 8

Good!

Answer 9

which is 2/15

Answer 10

So to clarify, we have 9 marbles left and there are initially 3 marbles so we have 3/9 chance of getting the yellow.

Then our total probability is 4/10*3/9 = 2/15 as you mentioned :)

Answer 11

3 yellow*

Answer 12

ty

Answer 13

Now lets look at the second question

Answer 14

Do you know factorials?

Answer 15

this is what i did
8^p4
8! / (8 - 4)!
5 * 6 * 7 * 8
1680

Answer 16

Looks good!

Answer 17

thnx