anonymous one year ago A bag has 5 red marbles, 6 blue marbles and 4 black marbles. What is the probability of picking a red marble, replacing it, and then picking a black marble?

1. misty1212

hi!!

2. misty1212

how many marbles total?

3. anonymous

15

4. misty1212

ok and haow many are red?

5. anonymous

5

6. misty1212

then what is the probability of picking a red one first?

7. anonymous

1/3 simplified

8. misty1212

right then you put the marble back, so there are still 15, how many are black?

9. anonymous

4

10. misty1212

so what is the probability of picking a black one ?

11. anonymous

4/15?

12. misty1212

yes

13. misty1212

14. misty1212

$\frac{1}{3}\times \frac{4}{15}$

15. anonymous

oh. i didnt know to multiply that. thank you!!