Last visit was: 18 Nov 2025, 17:21 It is currently 18 Nov 2025, 17:21
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 18 Nov 2025
Posts: 105,355
Own Kudos:
Given Kudos: 99,964
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,355
Kudos: 778,072
 [11]
1
Kudos
Add Kudos
10
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 18 Nov 2025
Posts: 105,355
Own Kudos:
778,072
 [5]
Given Kudos: 99,964
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,355
Kudos: 778,072
 [5]
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
General Discussion
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 18 Nov 2025
Posts: 8,423
Own Kudos:
4,979
 [2]
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,423
Kudos: 4,979
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
missionmba2025
Joined: 07 May 2023
Last visit: 07 Sep 2025
Posts: 341
Own Kudos:
427
 [2]
Given Kudos: 52
Location: India
Posts: 341
Kudos: 427
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
Two boxes, A and B, each contains only red and blue balls. If the ratio of red to blue balls in box A is 3 to 2, what is the probability of drawing red ball from box B ?

(1) The probability of drawing one blue ball from box A and one blue ball from box B is 3/10

(2) The probability of drawing at least one red ball, when drawing one ball from box A and one ball from box B, is 7/10


 


This question was provided by GMAT Club
for the Around the World in 80 Questions

Win over $20,000 in prizes: Courses, Tests & more

 


Number of balls in each of the box is as shown below -

BOX A -- RED = 3x
BOX A -- BLUE = 2x

BOX B -- RED = r
BOX B -- BLUE = b

Ques: r/(b+r) = ?

(1) The probability of drawing one blue ball from box A and one blue ball from box B is 3/10

2x/5x * b/(b+r) = 3/10

b/(b+r) = 3/4

Therefore r/(b+r) = 1- 3/4 = 1/4

Sufficient.

(2) The probability of drawing at least one red ball, when drawing one ball from box A and one ball from box B, is 7/10

1 - (both blue) = 7/10

1 - (2x/5x * b/(b+r)) = 7/10

2x/5x * b/(b+r) = 3/10

This is (1).

2x/5x * b/(b+r) = 3/10

b/(b+r) = 3/4

Therefore r/(b+r) = 1- 3/4 = 1/4

Sufficient.

IMO D
Moderators:
Math Expert
105355 posts
496 posts