reachskishore wrote:
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Hi Bunnuel,
This is similar to the post that you had replied
https://gmatclub.com/forum/if-a-pencil- ... 74394.html I totally agree with your answer for the post in this link. However, this similar question seems to have a different OA. I felt A would be enough if we were to solve this based on the explanation in the other question in the link.
Kindly let me know if I am right ? Or if the OA is right and I am making a mistake in analyzing the question.
Regards,
Kishore
Hi
The question that you have linked to is very similar to this question. But the first statement of this white ball question is slightly different from second statement of the linked pencil question. Lets write them down:
Statement 1, white ball question: There are twice as many white balls as
balls of any other colour.
So if the jar has only white and red balls, then if number of red balls is 'x', number of white balls is '2x'. And required probability of drawing a white ball = 2x/(2x+x) = 2/3
But if jar has white and red and blue balls, then if number of white balls = 2x, then no of red = no of blue = x each (twice as many white balls as balls of any other color)
In this case required probability = 2x/(2x+x+x) = 1/2
Answers can be different you see. So Insufficient.
Statement 2, pencil question: There are 3 times as many red pencils as pencils of
ALL other colors combined.
If you read carefully, this statement is different. It says no matter how many coloured pencils are there, if all other coloured pencils be 'x' in number combined, then number of red pencils = '3x'. So the ratio of red and non-red pencils will Always be 3:1 (unlike white ball question)..
So required probability in that case = 3/4 always.. Sufficient.
Hope this helps.