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

Question

dumbcow · Answer

6/15 * 5/15

anonymous · Answer

but these are the choices
8/75
3/5
2/15
4/45

anonymous · Answer

6/15*5/15 can be simplified to get to one of these answers :
6/15 = 2/5   (dividing both numerator and denominator by 3)
5/15 = 1/3   (dividing both numerator and denominator by 5)
2/5 * 1/3 will give you one of these answers

anonymous · Answer

2/15

anonymous · Answer

bingo

dumbcow · Answer

yeah you still have to simplify and reduce fractions...i was just showing you how to set it up
probability = desired outcomes/total outcomes

anonymous · Answer

A bag has 4 green marbles, 3 red marbles, and 3 yellow marbles. What is the probability that you pick a green marble, do not replace it, and pick a yellow marble?

1/15?

anonymous · Answer

close, but not quite. Can you show your working out so that I can explain what went wrong?

anonymous · Answer

oh my bad:
(3 [yellow]/10 [total])×(4 [green]/9 [total minus one]) = 12/90 = 2/15

anonymous · Answer

That's exactly it

anonymous · Answer

A bag has 4 green marbles, 3 red marbles, and 3 yellow marbles. What is the probability that you pick a green marble, do not replace it, and pick a red marble?

3/10

anonymous · Answer

Mathematically, what's different between this one and the last one?