Probability_blue marble

[Soumita Ghosh]

(1) The probability of drawing one blue marble is 6/35 .
(2) The probability of drawing no blue marbles is 4/35 .

What is the probability of drawing at least two blue marbles from a jar if three marbles are chosen?\

A.The probability of drawing one blue marble is .

B.The probability of drawing one blue marble is .

C.BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D.EACH statement ALONE is sufficient.

E.Statements (1) and (2) TOGETHER are NOT sufficient.

OA C

Bu my choice is D

From Statement A:

It is given the probability of drawing blue marble which is 6/35. From here we can find the probability of not drawing blue marble is 1-6/35=29/35

so from here we can find the probability at least two blue marbles from a jar if three marbles are chosen.

6/35*6/35*29/35 + 6/35*6/35*6/35

so statement A is sufficient

From Statement B:

The probability of drawing no blue marbles is 4/35. From here we can find the probability of drawing blue marble which is 1-4/35=31/35

So from here we can find the probability of at least two blue marbles from a jar if three marbles are chosen

So statement B is sufficient.

Therefore each statement is sufficient.

Please explain me where I am wrong!!

[Jim@StratusPrep]

I drop you a hint to start the conversation.... These probabilities are not for drawing 1 marble at a time, but rather 1 blue marble out of 3 or no blue marbles out of 3. We don't know the number of marbles or blue marbles in the jar...


Does that help?

I can keep going, but want to give you the opportunity to think it through...

[Soumita Ghosh]

Hi Jim,

thanks for your response !!

It is still not clear to me.

As per my understanding as we don't know the number of marbles or blue marbles in the jar we cannot find the probability from each statement alone.Then how can both statement is sufficient?

Please clear me !! I not good in probability !!

Is there any difference in meaning between the sentence the probability of drawing blue marble and the probability of drawing one blue marble?