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A bin contains 20 cards numbered from 1 to 20. If two cards are drawn
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18 Oct 2021, 05:28
18 Oct 2021, 05:28
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Question Stats:
69% (02:35) correct
30% (02:16) wrong based on 23 sessions
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A bin contains 20 cards numbered from 1 to 20. If two cards are drawn from the bin without replacement, what is the probability that the sum of the numbers on the cards is even ?
A. 1/3
B. 7/18
C. 4/9
D. 9/19
E. 1/2
A. 1/3
B. 7/18
C. 4/9
D. 9/19
E. 1/2
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Re: A bin contains 20 cards numbered from 1 to 20. If two cards are drawn
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18 Oct 2021, 06:02
18 Oct 2021, 06:02
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Carcass wrote:
A bin contains 20 cards numbered from 1 to 20. If two cards are drawn from the bin without replacement, what is the probability that the sum of the numbers on the cards is even ?
A. 1/3
B. 7/18
C. 4/9
D. 9/19
E. 1/2
A. 1/3
B. 7/18
C. 4/9
D. 9/19
E. 1/2
P(sum is even) = P(1st card is odd AND 2nd card is odd OR 1st card is even AND 2nd card is even)
= P(1st card is odd x P(2nd card is odd) + P(1st card is even) x P(2nd card is even)
= 10/20 x 9/19 + 10/20 x 9/19
= 1/2 x 9/19 + 1/2 x 9/19
= 9/38 + 9/38
= 18/38
= 9/19
Answer: D
Re: A bin contains 20 cards numbered from 1 to 20. If two cards are drawn
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20 Jul 2024, 06:56
20 Jul 2024, 06:56
1
The 2 numbered cards must be either odd or even.
Number of odd = 10
Number of even = 10
10C2 + 10C2/ 20C2 = 90/190
= 9/19
Adewale Fasipe, Lagos Nigeria.
Number of odd = 10
Number of even = 10
10C2 + 10C2/ 20C2 = 90/190
= 9/19
Adewale Fasipe, Lagos Nigeria.
