Question

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

Answer 1

How many red marbles are there @4everjames ?

Answer 2

@waterineyes 3

Answer 3

Similar to last question, just some changes:

In the beginning, the probability of a red marble is 3/10
After you've picked the first one and do not replace it, the probability of a red marble is 2/9.

So your statement would be:

Probability of red and red = Probability of 1st red * probability of 2nd red
= (3/10) * (2/9) = 6/90 = 1/15

Answer 4

Yes..
And what are total number of marbles that bag has?

Answer 5

@waterineyes 10

Answer 6

@mubzz thanksz!!!! i get it now thanks to u and @waterineyes

Answer 7

An easy tip to solve all probability questions:

When it says (prob of x) AND (prob of y)
you multiply, i.e. (prob of x)*(prob of y)

When it says (prob of x) OR (prob of y)
you add, i.e. (prob of x)+(prob of y)

Answer 8

ok just for review (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?