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There are 40 marbles in a jar. If of the marbles are blue
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09 Dec 2017, 18:38
09 Dec 2017, 18:38
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Question Stats:
91% (01:04) correct
8% (00:56) wrong based on 36 sessions
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There are 40 marbles in a jar. If \(\frac{1}{5}\) of the marbles are blue, \(\frac{1}{4}\) of the remaining marbles are red, and 10 marbles are green. If a marble is selected at random, then what is the probability that the marble will not be blue, red, or green?
Drill 2
Question: 10
Page: 529
Question: 10
Page: 529
Show: :: OA
\(\frac{14}{40}\)
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Re: There are 40 marbles in a jar. If of the marbles are blue
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23 Mar 2022, 11:53
23 Mar 2022, 11:53
1
sandy wrote:
There are 40 marbles in a jar. If \(\frac{1}{5}\) of the marbles are blue, \(\frac{1}{4}\) of the remaining marbles are red, and 10 marbles are green. If a marble is selected at random, then what is the probability that the marble will not be blue, red, or green?
Drill 2
Question: 10
Page: 529
Question: 10
Page: 529
Show: :: OA
\(\frac{14}{40}\)
There are 40 marbles in a jar, and 1/5 of the marbles are blue
1/5 of 40 = 8. So, there are 8 blue marbles.
1/4 of the remaining marbles are red
We have already accounted for 8 marbles, which means there are 32 marbles remaining.
So, the number of red marbles = 1/4 of 32 = 8
Also given: 10 marbles are green.
8 + 8 + 10 = 26
40 - 26 = 14, which means 14 of the 40 marbles are neither blue, red, or green
So, P(selected marble will not be blue, red, or green) = 14/40 = 7/20
Answer: 7/20 (or any equivalent fraction)
General Discussion
Re: There are 40 marbles in a jar. If of the marbles are blue
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29 Dec 2017, 15:29
29 Dec 2017, 15:29
Expert Reply
Explanation
First figure out how many marbles of each color are in the jar.
For blue:\(\frac{1}{5}\) of 40 is 8, so there are 8 blue marbles and 32 other marbles.
For red: \(\frac{1}{4}\) of 32 is 8, so there are 8 red marbles and 24 marbles that are neither red nor blue. As there are 10 green marbles, there are
14 marbles left that are not green, red, or blue.
Thus, the probability of selecting one of those marbles is \(\frac{14}{40}\).
If you answered \(\frac{26}{40}\), you found the probability that the selected marble will be blue, red, or green.
If you answered \(\frac{12}{40}\), for the red marbles you perhaps found \(\frac{1}{4}\) of 40 (the total marbles) rather than of 32 (the remaining marbles after blue) in the original calculation.
First figure out how many marbles of each color are in the jar.
For blue:\(\frac{1}{5}\) of 40 is 8, so there are 8 blue marbles and 32 other marbles.
For red: \(\frac{1}{4}\) of 32 is 8, so there are 8 red marbles and 24 marbles that are neither red nor blue. As there are 10 green marbles, there are
14 marbles left that are not green, red, or blue.
Thus, the probability of selecting one of those marbles is \(\frac{14}{40}\).
If you answered \(\frac{26}{40}\), you found the probability that the selected marble will be blue, red, or green.
If you answered \(\frac{12}{40}\), for the red marbles you perhaps found \(\frac{1}{4}\) of 40 (the total marbles) rather than of 32 (the remaining marbles after blue) in the original calculation.
