TestMagic Forums - View Single Post - A complete guide to Permutation, Combination and Probability. All you need for GMAT

mally · 04-21-2005, 08:09 PM

Hi,
Thanks for your answers , I'm solving the exercise and comparing my answers with yours.How did you do No.4-can u show me? your answer is D isn't it? I don't know why B is marked already.

A bag of 10 marbles contains 3 red marbles and 7 blue marbles. If two marbles are selected at random, what is the probability that at least one marble is blue?

A. 21/50

B. 3/13

C. 47/50

D. 14/15

E. 1/5

Thanks!

04-21-2005, 08:09 PM	#13 (permalink)
mally Eager! Join Date: Apr 2005 Location: Malvka,Atlanta Posts: 31	Re: A complete guide to Permutation, Combination and Probability. All you need for GMAT Hi, Thanks for your answers , I'm solving the exercise and comparing my answers with yours.How did you do No.4-can u show me? your answer is D isn't it? I don't know why B is marked already. A bag of 10 marbles contains 3 red marbles and 7 blue marbles. If two marbles are selected at random, what is the probability that at least one marble is blue? A. 21/50 B. 3/13 C. 47/50 D. 14/15 E. 1/5 Thanks!