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Sub 505 Level|   Probability|               
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parkhydel
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A box contains only white balls and black balls. What is the probabili 28 Apr 2020, 04:14
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C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

96% (00:25) correct 4% (00:33) wrong based on 1168 sessions

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A box contains only white balls and black balls. What is the probability that a ball selected at random from the box is white?

(1) There are 100 balls in the box.
(2) There are 40 black balls in the box.


ID: 700299
DS35330.02­
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C
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anilesh10
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A box contains only white balls and black balls. What is the probabili 28 Apr 2020, 04:56
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st1- not sufficient ,not given number of white balls
st2-not sufficient as we don't know the total number balls don't know the denominator.
combined sufficient c 60/100
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itspCv2
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A box contains only white balls and black balls. What is the probabili 11 May 2020, 12:39
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parkhydel
A box contains only white balls and black balls. What is the probability that a ball selected at random from the box is white?

(1) There are 100 balls in the box.
(2) There are 40 black balls in the box.


DS35330.02
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STRAIGHT to POINT: Probability = white/total


1)OK we need no. of white balls too( insufficient)
2)Ok we need total( insufficient)

Now combined: 100-40/100=probability
Therefore C
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karan12345
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A box contains only white balls and black balls. What is the probabili 01 Jun 2020, 21:31
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parkhydel
A box contains only white balls and black balls. What is the probability that a ball selected at random from the box is white?

(1) There are 100 balls in the box.
(2) There are 40 black balls in the box.


DS35330.02
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Statement 1 is insufficient as nothing about white balls.
Statement 2 is insufficient as no mention about white balls

On combining both, we get white balls are 60.

Hence, OA is C.
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A box contains only white balls and black balls. What is the probabili 30 Oct 2024, 09:08
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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).

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