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Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu

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Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 28 Jan 2018, 23:35
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

76% (01:40) correct 24% (01:40) wrong based on 101 sessions

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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 28 Jan 2018, 23:51
1
Answer is C.


Total number of possibilities is 20 out of which 3 will yield sum of 8

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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 13 Feb 2018, 10:55
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Bunuel wrote:
Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, numbered 5 - 9. What is the probability that the sum of a card pulled randomly from Bowl X and a card pulled randomly from Bowl Y will equal 8?

A. 1/20
B. 1/10
C. 3/20
D. 2/16
E. 3/16


NOTE: In order to get a sum of 8, the card selected from Bowl X must be 1, 2 or 3.
Here's why: Cards 1, 2 and 3 all have corresponding cards in Bowl Y that add to get 8 (i.e., 1+7 = 8, 2+6 = 8 and 3+5 = 8)
However, card 4 (from Bowl X) does NOT have a corresponding card in Bowl Y that add to get 8.

So P(sum is 8) = P(card selected from Bowl X is 1, 2 or 3 AND card selected from Bowl Y is the one card that works with the first card to get a sum of 8)
= P(card selected from Bowl X is 1, 2 or 3) x P(card selected from Bowl Y is the one card that works with the first card to get a sum of 8)
= 3/4 x 1/5
= 3/20

Answer: C

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Brent
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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 22 Oct 2019, 09:51
Bunuel, shouldn't the answer be 3/10, since I can pick a card from bowl X first or from bowl Y first, as the sequence is not specified. Thanks in advance for your responce.

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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 22 Oct 2019, 09:52
Bunuel, shouldn't the answer be 3/10, since I can pick a card from bowl X first or from bowl Y first, as the sequence is not specified. Thanks in advance for your response.

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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu  [#permalink]

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New post 26 Oct 2019, 08:55
Bunuel wrote:
Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, numbered 5 - 9. What is the probability that the sum of a card pulled randomly from Bowl X and a card pulled randomly from Bowl Y will equal 8?

A. 1/20
B. 1/10
C. 3/20
D. 2/16
E. 3/16


The total number of combinations (of a card drawn from Bowl X and another from Bowl Y) is 4 x 5 = 20. Of these 20 combinations, the ones that yield a sum of 8 are: 1 and 7, 2 and 6, and 3 and 5.

Therefore, the probability of getting a sum of 8 is 3/20.

Answer: C
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Re: Bowl X has 4 cards in it, numbered 1 - 4. Bowl Y has 5 cards in it, nu   [#permalink] 26 Oct 2019, 08:55
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