How many red marbles?

Expert replies

Vemuri: Legendary Member; Posts: 682; Joined: Fri Jan 16, 2009 2:40 amFollowed by: 1 member; Thanked: 32 times

by Vemuri » Tue Mar 17, 2009 6:26 pm

If each marble in a set of 50 marbles is either red, black or white, how many are red?

1. 25 marbles are not black and 40 marbles are not white
2. There are 15 more black marbles than white marbles, and 5 more red marbles than white marbles.

Like this post

Source: Beat The GMAT — Data Sufficiency | Tue Mar 17, 2009 6:26 pm

cramya: Legendary Member; Posts: 2467; Joined: Thu Aug 28, 2008 6:14 pmFollowed by: 11 members; Thanked: 331 times

by cramya » Tue Mar 17, 2009 6:57 pm

I would go wiht D

Stmt II

x-> white marbles

x+x+15+x+5 = 50

Solve for x then for red

Stmt I

40 marbles are not white i.e they are red or black.

10 white

25 not black-> can be red or white

25 black

If 10 are are white out of 25 then 15 has to be red.

SUFF

D

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review