## anonymous one year ago The table below shows the number of marbles of different colors in a bag: Ursula draws a marble from the bag randomly without looking. She then draws another marble from the bag without replacing the first one. Which expression shows the probability of drawing black marbles in both the trials?

1. anonymous

A

2. anonymous

B AND C

3. anonymous

4. anonymous

@Kash_TheSmartGuy

5. anonymous

Where is the table?

6. anonymous

here

7. anonymous

8. anonymous

i was thinking the answer would be a but idk

9. anonymous

Are you sure that's the table? The question asks about black marbles, but the table you provided only talks about Red, blue, green, and purple.

10. anonymous

crap wrong table

11. anonymous

12. anonymous

there but i was thinking (a) but im not sure

13. anonymous

When you look for a probability of one thing it's simply $\large \sf \frac{Desired~object}{Total~objcets}$ Which in this case is $\large \sf \frac{black~marbles}{Total~marbles}$ When you look for it to happen twice, you multiply the probabilities. Since we're assuming the first will end up with a loss of one black ( and one total ) the second probability would look like this $\large \sf \frac{black~marbles-1}{Total~marbles-1}$ Now you would just multiply the probabilities together so $\large \sf \frac{black~marbles}{Total~marbles}~\times ~ \large \sf \frac{black~marbles-1}{Total~marbles-1}$

14. anonymous

would it be a thats what i got

15. anonymous

No, it's not a

16. anonymous

c

17. anonymous

or b idk

18. anonymous

Why not just plug the numbers into what I gave you?

19. anonymous

$\large \sf \frac{black~marbles}{Total~marbles}~\times ~ \large \sf \frac{black~marbles-1}{Total~marbles-1}$

20. anonymous

idkhowwwwwwwwwwwwwwwwwwwwwwwwwwwwww

21. anonymous

How many black marbles are there?

22. anonymous

10

23. anonymous

How many total marbles are there?

24. anonymous

16

25. anonymous

26. anonymous

Now plug 10 in for black marbles and 16 for total marbles $\large \sf \frac{black~marbles}{Total~marbles}~\times ~ \large \sf \frac{black~marbles-1}{Total~marbles-1}$

27. anonymous

d

28. anonymous

You only showed A B and C as your options.

29. anonymous