MMM #16: Mario and the Problematic Yoshi
29 Sep 2008 Quan Quach 9 comments 9095 views

The Problem Statement
In one day, Mario has a 10 day showdown with Bowser at the Castle of Doom. In order to get there, Mario must mount Yoshi to traverse the Donut Plains. Unfortuantely, there is one slight problem.
Mario has a stable filled with 650 Yoshi Dinosaurs. Out of all these Yoshis, there is one Yoshi that always causes Mario problems. After riding this particular Yoshi (even for a second), Mario is too sore to do his usual jumps, sprints, and spin moves for 10 days. This debilitating injury makes it difficult to battle the goombas, koopa troopas, and other various baddies in the Mushroom Kingdom.
There’s a good chance that Mario will not ride the Problematic Yoshi but he doesn’t want to leave anything to chance. Luckily, Mario is a popular guy and has an infinite number of friends who are willing to help him out. But being the nice guy that he is, Mario wants to involve as few of his friends as possible in this ordeal.
What is the minimum number of friends that Mario will have to call upon to determine with 100% certainty which Yoshi is the Problematic Yoshi?
Assume the following:
1) There are 650 Yoshi Dinosaurs in the Stable.
2) All Yoshis are identical in appearance and behavior.
3) Riding the Problematic Yoshi for even a second will cause severe soreness for 10 days.
4) Soreness is not felt until after one day has passed.
5) Riding “Normal” Yoshis for any duration of time causes NO soreness.
6) Mario has an infinite number of friends of whom will help him test these Yoshis, i.e. Samus, Kirby, Link, Pikachu, Luigi, etc.
7) The answer is not 650 (it is obvious that Mario can call upon 650 of his friends and have them each ride a different Yoshi to determine the Problematic Yoshi).
The Bounty
The winner will receive a 10 dollar gift certificate to Amazon.com!
The Rules
-
Email your answers to mondaymathmadness at gmail dot com.
-
Depending on how many submissions we receive, we will be giving out additional prizes, giving you yet more chances to win. We’d also like to give a prize out to the “best” or “most creative” answer.
-
Inelgible for any one person to win more than once per year. But you should still submit your answer!
-
Answer must be explained. You must show your work! We will accept answers in the form of a MATLAB script as well. We will be the final judge on whether an answer was properly explained or not.
-
The deadline to submit answers is October 6th 2008, Monday 11:59 PM Pacific Standard Time
-
The winners will be chosen randomly from all the submittals using a random number generator.
-
The winner will be announced at 9:00 AM PST October 10th, 2008.
-
Comments for this post should only be used to clarify the problem. Please do not discuss ANY potential solutions.
-
Please spread the word about our contest by stumbling this webpage!
9 Responses to “MMM #16: Mario and the Problematic Yoshi”
Leave a Reply
Include MATLAB code in your comment by doing the following:
<pre lang="MATLAB">
%insert code here
</pre>

So 365 days are the maximum time allowed.?
Mario needs to do battle in one day. Therein lies the problem.
That’s 24 hours then?
Riding the Problematic Yoshi for even a second will cause severe soreness after a period of 23-25 hours.
even if there is infinite people riding the problematic yoshi, if all of them feel soreness only after a period of 25 hours, it still doesn’t meet the requirement…
blinkdagger is getting more and more popular!
YAY!!! go you!
so the time you have to find the problamatic Yoshi is 24 hours?? but the sourness can start after 25 hours?? HUH??
Mario needs just two friends.
10 are sufficient.
9 are not sufficient.
10 is the minimum.
Only one friend is necessary.
One friend rides one Yoshi; if that friend is sore after a day, then that Yoshi is the problematic one and he must pick from one of the other 649.
If that friend is not sore after a day, then he can just ride that Yoshi and be certain it is not the problematic Yoshi.
If the time allowed is 10 days.
Minimum is 6.
He has 9 days to find the bad yoshi.
The 10th day is reserved for testing.
Brands his yoshis to make sure this never happens again(or butchers the bad one).
Each day of testing results in one sore tester.
He splits his herd into 6 groups, one person rides each in that group. They are kept separate. The group that injured its rider is then split into 5, etc.
650/6! 1