Author: xi'an

Le Monde puzzle [#1066]

Recalling Le Monde mathematical puzzle  first competition problem For the X table below, what are the minimal number of lights that are on (green) to reach the minimal and maximal...continue reading.

riddles on a line [#2]

A second Riddle(r), with a puzzle related with the integer set Ð={,12,3,…,N}, in that it summarises as Given a random walk on Ð, starting at the middle N/2, with both...continue reading.

Le Monde puzzle [#1650]

A penultimate Le Monde mathematical puzzle  before the new competition starts [again!] For a game opposing 40 players over 12 questions, anyone answering correctly a question gets as reward the...continue reading.

riddles on a line

In the Riddler of August 18, two riddles connected with the integer set Ð={2,3,…,10}: Given a permutation of Ð, what is the probability that the most likely variation (up or...continue reading.

Le Monde puzzle [#1063]

A simple (summertime?!) arithmetic Le Monde mathematical puzzle A “powerful integer” is such that all its prime divisors are at least with multiplicity 2. Are there two powerful integers in...continue reading.

Le Monde puzzle [#1062]

A simple Le Monde mathematical puzzle none too geometric: Find square triangles which sides are all integers and which surface is its perimeter. Extend to non-square rectangles. No visible difficulty...continue reading.

Hamiltonian tails

“We demonstrate HMC’s sensitivity to these parameters by sampling from a bivariate Gaussian with correlation coefficient 0.99. We consider three settings (ε,L) = {(0.16; 40); (0.16; 50); (0.15; 50)}” Ziyu...continue reading.

seven digit addition

Another quick riddle from the riddler: solve the equation EXMREEK + EHKREKK = ?K?H?X?E which involves every digit between 0 and 9. While the puzzle can be unravelled by considering...continue reading.

Le Monde puzzle [#1051]

A combinatoric Le Monde mathematical puzzle of limited size: When the only allowed move is to switch two balls from adjacent boxes, what is the minimal number of moves to...continue reading.

Le Monde puzzle [#1045]

An minor arithmetic Le Monde mathematical puzzle: Take a sequence of 16  integers with 4 digits each, separated by 2,  such that it contains a perfect square and its sum...continue reading.