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From a jar containing 4 red and 2 white marbles, Lionel draw
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15 Apr 2020, 08:38
15 Apr 2020, 08:38
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Question Stats:
81% (01:01) correct
18% (02:21) wrong based on 43 sessions
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From a jar containing 4 red and 2 white marbles, Lionel draws two marbles simultaneously and at random. What is the probability that he picks one marble of each color?
A. 3/5
B. 8/15
C. 7/15
D. 2/5
E. 7/30
A. 3/5
B. 8/15
C. 7/15
D. 2/5
E. 7/30
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Re: From a jar containing 4 red and 2 white marbles, Lionel draw
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15 Apr 2020, 09:22
15 Apr 2020, 09:22
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Carcass wrote:
From a jar containing 4 red and 2 white marbles, Lionel draws two marbles simultaneously and at random. What is the probability that he picks one marble of each color?
A. 3/5
B. 8/15
C. 7/15
D. 2/5
E. 7/30
A. 3/5
B. 8/15
C. 7/15
D. 2/5
E. 7/30
P(one of each color) = P(1st is red AND 2nd is white OR 1st is white AND 2nd is red)
= P(1st is red AND 2nd is white) + P(1st is white AND 2nd is red)
= [P(1st is red) x P(2nd is white)] + [P(1st is white) x P(2nd is red)]
= [4/6 x 2/5]+ [2/6 x 4/5]
= 8/30+ 8/30
= 16/30
= 8/15
Answer: B
Cheers,
Brent
Re: From a jar containing 4 red and 2 white marbles, Lionel draw
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15 Apr 2020, 10:28
15 Apr 2020, 10:28
1
i will go with negation method.
lets both are of same colour
so i 2 white .no. of ways choosing 2 white out of 2=1=2cc
4red. no. of ways choosing 2 reds out of 4=4c2=4*3*2*1/2*2^=6
so total ways of getting both balls of same colour^=1+6=7
no. of ways choosing 2 out of 6 balls=6c2=. 15
so probability that balls are of different colours= 1-probability that both balls are of same colour
=1-7/15
8/15
lets both are of same colour
so i 2 white .no. of ways choosing 2 white out of 2=1=2cc
4red. no. of ways choosing 2 reds out of 4=4c2=4*3*2*1/2*2^=6
so total ways of getting both balls of same colour^=1+6=7
no. of ways choosing 2 out of 6 balls=6c2=. 15
so probability that balls are of different colours= 1-probability that both balls are of same colour
=1-7/15
8/15
