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Learn how Kamakshi achieved a GMAT 675 with an impressive 96th %ile in Data Insights. Discover the unique methods and exam strategies that helped her excel in DI along with other sections for a balanced and high score.
19 May 2025, 21:52
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Number of
Marbles: 40 Probability of
Red (in %): 50
Marbles: 40 Probability of
Red (in %): 50
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
76% (01:54) correct
24%
(02:04)
wrong
based on 405
sessions
History
Date
Time
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Not Attempted Yet
Julia is about to draw a marble from a bag that contains red, white, and blue marbles. Currently there are 10 red marbles, 20 white marbles, and 30 blue marbles, and Julia would like to draw a red marble. From the table below, select the number of red marbles that would have to be added to the bag in order to reach the new probability of Julia drawing a red marble.
|
Number of Marbles |
Probability of Red (in %) |
|
| 10 | ||
| 20 | ||
| 30 | ||
| 40 | ||
| 50 |
ShowHide Answer
Official Answer
Number of
Marbles: 40 Probability of
Red (in %): 50
Marbles: 40 Probability of
Red (in %): 50
poojaarora1818
Joined: 30 Jul 2019
Last visit: 02 May 2026
Posts: 1,634
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Location: India
Concentration: General Management, Economics
Schools: Duke '27 Haas '27 Kelley '27 Kellogg '27 McDonough '27
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20 May 2025, 01:20
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solution:
We have already been given 10 Red, 20 White, and 30 Blue marbles. So, the total number would be 60. Currently, the probability of red marbles is \(\frac{10}{60}\) = \(\frac{1}{6}\). Now, we can check the new probability of Julia drawing a red marble by checking against the percentage given to us. Let's consider the new value added to this, which is x. Since we are not told how much new value is to be added to get to the solution.
1.\(\frac{ (10 + x)}{(60 + x) }\)= 10% (Not possible)
2.\( \frac{(10 + x)}{(60 + x)}\) = 20% (Not possible)
3.\( \frac{(10 + x)}{(60 + x) }\)= 30% (Not possible)
4.\( \frac{(10 + x)}{(60 + x) }\)= 40%(Not possible)
5.\(\frac{ (10 + x)}{(60 + x)}\) = 50% (possible). Here, we will get the value for x as 40. So, the number of red marbles that should be added is 40, and 50% is our new probability.
We have already been given 10 Red, 20 White, and 30 Blue marbles. So, the total number would be 60. Currently, the probability of red marbles is \(\frac{10}{60}\) = \(\frac{1}{6}\). Now, we can check the new probability of Julia drawing a red marble by checking against the percentage given to us. Let's consider the new value added to this, which is x. Since we are not told how much new value is to be added to get to the solution.
1.\(\frac{ (10 + x)}{(60 + x) }\)= 10% (Not possible)
2.\( \frac{(10 + x)}{(60 + x)}\) = 20% (Not possible)
3.\( \frac{(10 + x)}{(60 + x) }\)= 30% (Not possible)
4.\( \frac{(10 + x)}{(60 + x) }\)= 40%(Not possible)
5.\(\frac{ (10 + x)}{(60 + x)}\) = 50% (possible). Here, we will get the value for x as 40. So, the number of red marbles that should be added is 40, and 50% is our new probability.
Bismuth83
21 May 2025, 07:36
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Bismuth83, can you provide the OA?
