GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 22 Oct 2019, 07:38

### 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

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

# A bag contains only 3 different colours and atleast one ball of red

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Aug 2009
Posts: 8006
A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

Updated on: 13 Feb 2017, 19:33
2
5
00:00

Difficulty:

75% (hard)

Question Stats:

49% (01:32) correct 51% (01:25) wrong based on 124 sessions

### HideShow timer Statistics

A bag contains only 3 different colours and atleast one ball of red, white and blue colour. If the number of balls of each colour is distinct and red coloured balls are more than each of the other two colours, what is the probability of picking red ball?

(1) number of blue and white ball is half of total number of ball.
(2) there are 3 red coloured balls.

_________________

Originally posted by chetan2u on 13 Feb 2017, 05:46.
Last edited by chetan2u on 13 Feb 2017, 19:33, edited 2 times in total.
Renamed the topic.
Intern
Joined: 14 May 2014
Posts: 16
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

13 Feb 2017, 09:18
I think its A
(1) P picking red ball = 1/2
(2) no info about total ball number
Intern
Joined: 18 Jan 2017
Posts: 1
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

13 Feb 2017, 10:52
Hi,

I think it's D.

For statement 2:
Though the total number of balls was not mentioned, We can estimate the number of blue and white balls from the condition given in the question "the number of balls of each colour is distinct and red coloured balls are more than each of the other two colours".

So, the only possibility is that the number of blue and white colour balls are 2 and 1.

Then the probability of selecting a red ball is again 1/2.

Intern
Joined: 08 Jan 2017
Posts: 26
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

13 Feb 2017, 11:06
chetan2u wrote:
A bag contains only 3 different colours and atleast one ball of red, white and blue colour. If the number of balls of each colour is distinct and red coloured balls are more than each of the other two colours, what is the probability of picking red ball?

(1) number of blue and white ball is half of total number of ball.
(2) there are 3 red coloured balls.

Hi,

rephrase the stem question to R/(R+W+B) ?

1. it says W+B=(W+B+R)/2 ---> W+B=R put it back in above equetion and it gives 1/2. sufficient
2. if there are 3 red balls and in stem it says the number of balls differ, there are more reds than other two and at least 1 of each exist then either w=1,B=2 or b=1,w=2. therefore sufficient.

have fun.
Math Expert
Joined: 02 Aug 2009
Posts: 8006
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

13 Feb 2017, 19:38
2
trangphamthuy91 wrote:
I think its A
(1) P picking red ball = 1/2
(2) no info about total ball number

Hi
Relook in the statement II..
Red ball are 3, buy the other info is..
1) red is max and ATLEAST one of each colour
2) all three are distinct number..

So clearly red is 3 and other 2 are 1 and 2..
Now we can find probability
_________________
Director
Joined: 14 Nov 2014
Posts: 598
Location: India
GMAT 1: 700 Q50 V34
GPA: 3.76
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

14 Feb 2017, 02:44
chetan2u wrote:
A bag contains only 3 different colours and atleast one ball of red, white and blue colour. If the number of balls of each colour is distinct and red coloured balls are more than each of the other two colours, what is the probability of picking red ball?

(1) number of blue and white ball is half of total number of ball.
(2) there are 3 red coloured balls.

D ..

A .(B+W) = 1/2x , R = 1/2x
p = 1/2
suff

B.Given red = 3 .. and in the question stem it is mentioned that number of each color is distinct and the bag have atlst one ball of each color ...so the possible value of red and blue will be 2,1 or 1,2
so p = 3/6 =1/2..
suff

So D.
Intern
Joined: 03 Feb 2017
Posts: 25
A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

19 Feb 2017, 01:35
R>W and R>B

1) B+W= B+W+R/2 => 2B+2W=B+W+R => B+W=R
Probability of picking Red is R/B+W+R => R/R+R =R/2R Sufficient
2) R=3; So, W and B could be 1,2 or 2,1 => probability is 3/3+2+1 Sufficient
Non-Human User
Joined: 09 Sep 2013
Posts: 13393
Re: A bag contains only 3 different colours and atleast one ball of red  [#permalink]

### Show Tags

25 Oct 2018, 22:49
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: A bag contains only 3 different colours and atleast one ball of red   [#permalink] 25 Oct 2018, 22:49
Display posts from previous: Sort by