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# Christmas Math

Tue 9 Dec, 2008 05:44 pm
Mr. Johnson is 31 years old. This Christmas will be his 34th. His niece is 30 and has celebrated 29 Christmases. How is this possible?
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Type: Question • Score: 0 • Views: 13,803 • Replies: 20
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George

2
Tue 9 Dec, 2008 05:50 pm
@libertydawn,
Please tell me this doesn't involve the International Date Line.
libertydawn

1
Tue 9 Dec, 2008 05:56 pm
@George,
I wondered if it was something like that, too. I am not sure, though. It is an extra credit assignment that my brother has for a class he is doing poorly in. He has been trying to figure it out and I have been trying to help, but neither of us have had much luck so I thought I would try this site and maybe someone would know the answer or at least be able to give a helpful hint or two.
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boomerang

1
Wed 10 Dec, 2008 07:53 am
I think George is right -- they cross the international date line.
lmur

1
Wed 10 Dec, 2008 08:01 am
@boomerang,
Given that they're uncle and niece; dating would be crossing the line all right...
George

1
Wed 10 Dec, 2008 08:44 am
@lmur,
tiddy-boom!
0 Replies

1
Wed 10 Dec, 2008 08:44 am
Perhaps the niece just didn't celebrate one year....
Robert Gentel

1
Wed 10 Dec, 2008 12:31 pm
The niece is easy, her birthday is before Christmas, now Mr. Johnson is tough, even if his birthday is after Christmas that only gets us 1 and we need two more.
boomerang

1
Wed 10 Dec, 2008 12:34 pm
@Robert Gentel,
If his birthday is on Christmas day you can add two, but you still need one more.
0 Replies

1
Wed 10 Dec, 2008 01:14 pm
@Robert Gentel,
Actually, a birthday before or after Christmas doesn't matter. You are zero when you're born; by the time of your first birthday, you've passed Dec. 25th one time.

So at 30, one should have passed Dec. 25th 30 times. (Ignoring the International Date Line, of course.)
Robert Gentel

1
Wed 10 Dec, 2008 01:26 pm
You are zero when you're born;

Depending on where in the world you are, other cultures don't necessarily count it this way:

http://en.wikipedia.org/wiki/East_Asian_age_reckoning

Quote:
Newborns start at one year old, and each passing of a New Year, rather than the birthday, adds one year to the person's age; this results in people being between 1 and 2 years older in Asian reckoning than in the Western version.

1
Wed 10 Dec, 2008 01:28 pm
@Robert Gentel,
With a name like "Mr. Johnson" I'm gonna assume they're not East Asian, mkay?
0 Replies

Butrflynet

1
Wed 10 Dec, 2008 01:47 pm
Mr. Johnson is 31 years old.
This Christmas will be his 34th. (So he has only experienced 33 of them to date.)

If he was born on December 25th, it would be his first Christmas. On his first birthday the next year, it would be his second Christmas, etc., etc. So, on Christmas day last year he was 31 and had seen his 32nd Christmas.

Meanwhile, His niece is 30 and has celebrated 29 Christmases.

How is this possible?

One year, on December 24th his niece traveled across the international date line in one direction and by the time she got there it was already December 26th so she didn't celebrate Christmas that year. (It doesn't change her age, just the number of Christmas celebrations.)

Last year, (his 31st birthday and 32nd Christmas) Mr. Johnson decided to visit her on his birthday (Christmas Day). He had a birthday and Christmas celebration at his home and then flew in the opposite direction across the international date line and when he arrived, he got to celebrate a second Christmas with his niece (making that his 33rd Christmas).

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libertydawn

1
Wed 10 Dec, 2008 03:13 pm
it has nothing to do with the international date line or different time zones also does not involve being a different religion that might celebrate on a different date.
Butrflynet

1
Wed 10 Dec, 2008 03:18 pm
@libertydawn,
If those facts are known to you then why aren't they mentioned in your original post?

What facts were provided with the assignment that you did not include in the original post?
libertydawn

1
Wed 10 Dec, 2008 03:49 pm
@Butrflynet,
actually teacher just mentioned those new facts today when someone thought they had the answer ...sorry
libertydawn

1
Mon 15 Dec, 2008 04:00 pm
@libertydawn,
Ok...so my little brother is a bad source of information that changes from one day to the next and I apologize for any confusion, but I think I finally nailed him down on the exact wording and I think it may make a difference.

"Mr. Johnson is 31. This year will be his 34th Christmas. His niece is 30 and has had 29 Christmases. How is this possible?"

It is not much different, I know...which is why he thought the wording was not a big deal. Anyone with much experience with riddles, though, knows that wording is everything. If 31 and 30 do not, in fact, refer to their ages, this could be something entirely different.

Any thoughts?
Mr Stillwater

1
Tue 16 Dec, 2008 03:23 am
@libertydawn,
If my Johnson was 31, all my Christmases would come at once.
0 Replies

nivesh

1
Sun 12 Jul, 2009 11:38 pm
@libertydawn,
ok the man is 31 fine...
he will have celebrated 34 christmases making him 34 years old (3 years after he turned 31)

his niece is 30 as the previouse year she was 29 and she turned 29 and the following year she turned 30 befor Christmas

Nivesh
0 Replies

nivesh

1
Sun 12 Jul, 2009 11:39 pm
@libertydawn,
ok the man is 31 fine...
he will have celebrated 34 christmases making him 34 years old (3 years after he turned 31)

his niece is 30 as the previouse year she was 29 and she turned 29 and the following year she turned 30 befor Christmas

Nivesh
0 Replies

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