Math Challenge

Welcome to Crypto. We hope you enjoy your visit.

You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free.

Join our community!

If you're already a member please log in to your account to access all of our features:

Math Challenge; Seen as this is an off topic...
Topic Started: Oct 20 2005, 04:22 PM (398 Views)
cows	Oct 20 2005, 04:22 PM Post #1
Advanced Member Posts: 91 Group: New Members Member #20 Joined: October 10, 2005	This is a challenge i heard about and wondered what you thought: A man has a year (365 days) to hack as many computers as possible. On the nth day of a week, the maximum number of people he is allowed to hack is n2 + 2, otherwise he goes to jail. During the nth day of the month, the maximum number of computers he can hack is n, otherwise he will be banished (and can no longer hack computers ). Compute the maximum number of computers this elite hack can hack from January 1st (Monday) to the end of the year. How long does it take you ???? Ignore the part about the hacking computers - its just used as an example on the page i got it from.
	Everything is possible, The impossible just takes longer If we do not know what a particle is doing then it is allowed t do everything possible simultaneously. "Anyone who can contemplate Quantum Mechanics without getting dizzy, didn't understand it."


insecure	Oct 20 2005, 04:59 PM Post #2
Elite member Posts: 381 Group: Trusted Member Member #10 Joined: September 9, 2005	He can hack as many as he likes, provided he doesn't mind going to jail or being banished. For example, he could hack 100,000,000 machines on 31st December.



cows	Oct 21 2005, 09:00 AM Post #3
Advanced Member Posts: 91 Group: New Members Member #20 Joined: October 10, 2005	Please Explain?
	Everything is possible, The impossible just takes longer If we do not know what a particle is doing then it is allowed t do everything possible simultaneously. "Anyone who can contemplate Quantum Mechanics without getting dizzy, didn't understand it."


insecure	Oct 21 2005, 10:04 AM Post #4
Elite member Posts: 381 Group: Trusted Member Member #10 Joined: September 9, 2005	I think you probably intended to use a wording such as "Compute the maximum number of computers this elite hack can hack from January 1st (Monday) to the end of the year without ending up in jail or being banished." Because you didn't, the answer is as I stated - i.e. he can hack as many machines as he likes as long as he is unconcerned about the consequences. He is limited only by physical constraints such as the number of connected machines on the planet, etc etc. As Donald has discovered recently, setting a challenge or a puzzle or a quiz is hard work - if you don't wish to be misunderstood, you have to be fairly precise.



Revelation	Oct 21 2005, 10:17 AM Post #5
Administrator Posts: 386 Group: Admin Member #1 Joined: August 23, 2005	This looks like nonsense to me. First you claim he can hack 2n+2 computers a day. So y = 2n+2, where y is the number of PCs. Then you say that on the Nth day, he can hack N computers, so y=n. that makes n=2n+2=>n=-2, because a day in the month is also a day in the week.
	RRRREJMEEEEEPVKLWENFNVJKEEEEEAOLKAFKLXCFZAASDJXZTTTTTTTLSIOWJXMOKLAFJNNKFNXN RAGRBAQEMHIGDJVDSEOXVIYCELFHWLELJFIENXLRATALSJFSLCYTKLASJDKMHGOVOKAJDNMNUITN RRRRLJVEEEEECLYVYHNVPFTAEEEEEMWLMEIRNGLARWJAKJDFLWNTIERJMIPQWOTZEOCXKNUBNXCN RJIRPOWEANFUSNCZVDVZNMSFEKLOEPZLDKDJWSAAAAAAAOERHJCTNCKFRIMVKSOFOMKMANREWNBN RZUDRGXEEEEENFQIDVLQNCKNEEEEEDGLLLLLLAWIOSNCDARLODMTOEJXMILDFJROTKJSDNLVCZNN


cows	Oct 21 2005, 10:20 AM Post #6
Advanced Member Posts: 91 Group: New Members Member #20 Joined: October 10, 2005	Thanks for that - i have told the person who made it and am waiting for his response - well done for noticing it - i didn't
	Everything is possible, The impossible just takes longer If we do not know what a particle is doing then it is allowed t do everything possible simultaneously. "Anyone who can contemplate Quantum Mechanics without getting dizzy, didn't understand it."


insecure	Oct 21 2005, 10:46 AM Post #7
Elite member Posts: 381 Group: Trusted Member Member #10 Joined: September 9, 2005	Revelation Oct 21 2005, 10:17 AM This looks like nonsense to me. First you claim he can hack 2n+2 computers a day. So y = 2n+2, where y is the number of PCs. Then you say that on the Nth day, he can hack N computers, so y=n. that makes n=2n+2=>n=-2, because a day in the month is also a day in the week. He actually said n2 + 2, not 2n + 2. I think he meant n * n + 2 (i.e. n to the power 2, plus 2). The following reasoning assumes this, but if he did mean 2n + 2 then the mathematics should be adjusted accordingly, but the logic still works even though the numbers will be different. So, during a week he can hack: Code: `Day Hackable machines 1 3 2 6 3 11 4 18 5 27 6 38 7 51` without going to jail. However, there is an additional constraint, which is that he can't hack more than n machines on day n of the month without being banned from hacking. So, if we keep this example simple by restricting our attention to January, where the beginning of the week coincides with the beginning of the month, the above table becomes 1, 2, 3, 4, 5, 6, 7 for the first week. In the second week, it becomes 3, 6, 10, 11, 12, 13, 14. In the third week, it will be 3, 6, 11, 18, 19, 20, 21. In the fourth, it will be 3, 6, 11, 18, 26, 27, 28. And the fifth week (in which we roll over to Feb halfway through), it will be 3, 6, 11, 1, 2, 3, 4. Get the idea now?



cows	Oct 21 2005, 11:46 AM Post #8
Advanced Member Posts: 91 Group: New Members Member #20 Joined: October 10, 2005	Sorry Guys - forgot to mention that n2 + 2 is supposed to be n^2+2 or n*n+2. Oops.
	Everything is possible, The impossible just takes longer If we do not know what a particle is doing then it is allowed t do everything possible simultaneously. "Anyone who can contemplate Quantum Mechanics without getting dizzy, didn't understand it."


1 user reading this topic (1 Guest and 0 Anonymous)


« Previous Topic · Off-topic · Next Topic »