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# Each baby born at a certain hospital last week was either a

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Retired Moderator
Joined: 29 Oct 2013
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Each baby born at a certain hospital last week was either a  [#permalink]

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05 Jun 2014, 03:29
4
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Difficulty:

25% (medium)

Question Stats:

73% (01:03) correct 27% (01:04) wrong based on 255 sessions

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Each baby born at a certain hospital last week was either a single birth or one of a pair twins. If x is the number of babies born at the hospital last week, is x odd?

1. There were 33 single births at the hospital last week
2. There were 3 pairs of twins born at the hospital last week

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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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05 Jun 2014, 03:31
1
St1: No matter how many twins were born along with 33 singles total number will always be odd. SUFF
St2: We need to know the no. of singles to ascertain whether the total was odd. INSUFF

Ans : A
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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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05 Jun 2015, 17:20
I quickly set up the formula

S +2T= X . From the formula you can realize that the number of twins will always be even (there's 2 of them) so you can look at this as S + Even= Odd? Thus the question can be rephrased as is the number of single babies born odd? Thus statement 1 sufficient and statement 2 insufficient.
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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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06 Jun 2015, 11:17
Hi All,

This DS prompt serves as a nice example of how doing some 'up-front' work BEFORE you deal with the 2 Facts can help you to spot any inherent patterns in the question.

Here, we're told that we have a certain number of single babies and a certain number of twins born in a hospital. We're told that the TOTAL number of babies is X. We're asked if X is ODD?

Since twins come 'two-at-a-time', there will always be an EVEN number of twins. It's the number of SINGLE babies that will determine whether X is ODD or EVEN. Making THAT deduction up front makes dealing with the 2 Facts a remarkably simple task.

If you get in the habit of taking notes and putting in a little work up-front, you'll find that a number of DS questions on Test Day become considerably easier to answer.

GMAT assassins aren't born, they're made,
Rich
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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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21 Jun 2017, 11:34
EMPOWERgmatRichC wrote:
Hi All,

This DS prompt serves as a nice example of how doing some 'up-front' work BEFORE you deal with the 2 Facts can help you to spot any inherent patterns in the question.

Here, we're told that we have a certain number of single babies and a certain number of twins born in a hospital. We're told that the TOTAL number of babies is X. We're asked if X is ODD?

Since twins come 'two-at-a-time', there will always be an EVEN number of twins. It's the number of SINGLE babies that will determine whether X is ODD or EVEN. Making THAT deduction up front makes dealing with the 2 Facts a remarkably simple task.

If you get in the habit of taking notes and putting in a little work up-front, you'll find that a number of DS questions on Test Day become considerably easier to answer.

GMAT assassins aren't born, they're made,
Rich

yes youre right. I got it wrong and you cannot image how I feel about it
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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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21 Jun 2017, 11:45
1
I will go with A

(1) 33 is odd and twins are even so odd + even will always be odd ...sufficient

(2) twin is even but single birth/s can be even or odd. Hence insufficient

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Re: Each baby born at a certain hospital last week was either a  [#permalink]

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09 Aug 2018, 12:13
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

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Re: Each baby born at a certain hospital last week was either a   [#permalink] 09 Aug 2018, 12:13
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