## Le Monde puzzle [#1078]

Posted in Books, Kids, R with tags , , , , , , on November 29, 2018 by xi'an

Recalling Le Monde mathematical puzzle  first competition problem

Given yay/nay answers to the three following questions about the integer 13≤n≤1300 (i) is the integer n less than 500? (ii) is n a perfect square? (iii) is n a perfect cube?  n cannot be determined, but it is certain that any answer to the fourth question (iv) are all digits of n distinct? allows to identify n. What is n if the answer provided for (ii) was false.

When looking at perfect squares less than 1300 (33) and perfect cubes less than 1300 (8), there exists one single common integer less than 500 (64) and one single above (729). Hence, it is not possible that answers to (ii) and (iii) are both positive, since the final (iv) would then be unnecessary. If the answer to (ii) is negative and the answer to (iii) is positive, it would mean that the value of n is either 512 or 10³ depending on the answer to (i), excluding numbers below 500 since there is no unicity even after (iv). When switching to a positive answer to (ii), this produces 729 as the puzzle solution.

Incidentally, while Amic, Robin, and I finished among the 25 ex-aequos of the competition, none of us reached the subsidiary maximal number of points to become the overall winner. It may be that I will attend the reward ceremony at Musée des Arts et Métiers next Sunday.

## MCMSki IV, Jan. 6-8, 2014, Chamonix (news #4)

Posted in Mountains, R, Statistics, University life with tags , , , , , , , , , , , , , , , on March 10, 2013 by xi'an

More news about MCMSki IV! Remember, the call is still open for contributed sessions for a few more weeks, till March. 20 to be precise (make sure to contact me at bayesianstatistics@gmail.com if you are considering putting one session together). To all those who already submitted a session, thanks a lot, please stay tuned, and we will contact you very soon after March 20!

One exciting item is that there will be a satellite workshop on January 9, on Bayesian non-parametrics and semi-parametrics, organised by Judith Rousseau. BNPski, anyone?!  Details are not yet available, but anyone registered for MCMSki IV and interested should be free to attend this workshop, free of charges. (It will take place at the conference centre as well.)

Another item is that we managed to get a cheaper offer for the ski race, reaching an entry prize of 10 euros. Or less if we manage to find this sponsor… Not that bad when considering the high probability competitors have to win a pair of skis!!!

Last item for today: the list and rate of hotels available thru the conference centre is as follows

• ALPINA*** : Single Room 136€ & Twin or Double Room 106€ /pers
• PRIEURE*** : Single Room 136€ & Twin or Double Room 106€ /pers
• LOUVRE** : Single Room 85 € & Twin or Double Room 64€ /pers
• POINTE ISABELLE** : Single Room 81,90€ & Twin or Double Room 59,90€ /perss

However, many other options are available in the vicinity, from hotels to B&B, to rental apartments and chalets, with a wide range of prices if you pre-book early (like now!) See the links on our webpage.

## MCMSki IV, Jan. 6-8 (9?), 2014, Chamonix (news #3)

Posted in Mountains, R, Statistics, University life with tags , , , , , , , , , , , , , , on February 5, 2013 by xi'an

In case you have not been constantly tracking the changes on the MCMSki IV webpage, here are some news: the number of invited and accepted contributed sessions in the program had considerably increased, to the point of almost filling two parallel sessions for the whole duration of the meeting. This includes an exciting round-table on MCMC software animated by Luke Bornn. We are actually discussing how to handle the incoming proposals, from adding one more track/room to the program to adding an extra morning (the morning after!) to the meeting—with the argument that participants will anyway leave on the 9th of January at the earliest—to sadly rejecting some of the proposed contributed sessions…. Nonetheless, the call is still open for contributed sessions for a few more weeks, till March. 20 to be precise (make sure to contact me at bayesianstatistics@gmail.com if you are considering putting one session together).

The registration page is not yet complete (we are still discussing the rates for the Richard Tweedie ski race, and managed to get them down to 10€ per person so far so we may not have to cancel this race, especially given the exciting (almost certain!) promise of a pair of brand new skis for the winners!, and more we can find benevolent sponsors…). Once again the conference fees will range from 100€ for PhD students to 210€ for participants not members of ISBA or of IMS. The additional fees for the banquet have also been lowered to 30 euros.