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Algebra

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16 Jan 2009 10:47:37 IST

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I tore several successive pages out of a book. The number of the first page I tore was 183 while the number of the last page was written with the same digits in some order. How many pages did I tear out of the book?

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Debotosh Chatterjee

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16 Jan 2009 11:03:10 IST

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either 315 or 68------------ I AM NOT SURE.........

Rahul Duggal

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16 Jan 2009 16:09:28 IST

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first we observe that in every book, we have a page numbered with an odd integer on the right hand side and with an even integer on the left hand side.

continuing this we know every time we tear one page, we are actually tearing 2 sides. eg if we tear pg 183, page 184 also comes along with that.

so we know every time we tear a page numbered 2n we also end up tearing (2n-1)th page. so the last side of a page we are tearing is always even.

so only possibility we have is the last page being 318.

so the the number of pages torn by us is (318-183 +1)/2 = 68 pages or 136 sides

PLEASE CORRECT ME IF IM WRONG

Anant Kumar

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17 Jan 2009 11:57:18 IST

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Absolutely right rahul.

Debotosh Chatterjee

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18 Jan 2009 22:01:48 IST

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what is the correct answer????????

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