Good numbers [self-made]
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Phlembac Adib Hasan
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A number is called good if exactly six of its digits are $1$ and the rest of the digits are all zero. Find the number of good integers between $10^7$ and $2\cdot 10^{13}$.
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Farhan Uddin
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Re: Good numbers [self-made]
আচ্ছা, 2A দিয়ে কী বুঝানো হইসে?
Last edited by Phlembac Adib Hasan on Fri Apr 05, 2013 2:41 pm, edited 1 time in total.
Reason: Transliterated
Reason: Transliterated
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Phlembac Adib Hasan
- Posts:1016
- Joined:Tue Nov 22, 2011 7:49 pm
- Location:127.0.0.1
- Contact:
Re: Good numbers [self-made]
2A কোত্থেকে পেলেন? সংখ্যা তো দিলাম মোটে দুইটা- $10^7$ (টেন টু দ্য পাওয়ার সেভেন) আর $2\cdot 10^{13}$ (টু ইনটু টেন টু দ্য পাওয়ার থার্টিন)Farhan Uddin wrote:আচ্ছা, 2A দিয়ে কী বুঝানো হইসে?
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Thanic Nur Samin
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Re: Good numbers [self-made]
$\sum_{n=8}^{13}$ $ ^{8}P_n+ ^{13}P_5$
Hammer with tact.
Because destroying everything mindlessly isn't cool enough.
Because destroying everything mindlessly isn't cool enough.