mscroggs.co.uk
mscroggs.co.uk

subscribe

Blog

 2019-09-01 
This week, I've been in Cambridge for Talking Maths in Public (TMiP). TMiP is a conference for anyone involved in—or interested in getting involved in—any sort of maths outreach, enrichment, or public engagement activity. It was really good, and I highly recommend coming to TMiP 2021.
The Saturday morning at TMiP was filled with a choice of activities, including a treasure punt (a treasure hunt on a punt) written by me. This post contains the puzzle from the treasure punt for anyone who was there and would like to revisit it, or anyone who wasn't there and would like to give it a try. In case you're not current in Cambridge on a punt, the clues that you were meant to spot during the punt are given behing spoiler tags (hover/click to reveal).

Instructions

Each boat was given a copy of the instructions, and a box that was locked using a combination lock.
The instructions, download a pdf here.
Locked boxes.
If you want to make your own treasure punt or similar activity, you can find the LaTeX code used to create the instructions and the Python code I used to check that the puzzle has a unique solution on GitHub. It's licensed with a CC BY 4.0 licence, so you can resuse an edit it in any way you like, as long as you attribute the bits I made that you keep.

The puzzle

Four mathematicians—Ben, Katie, Kevin, and Sam—each have one of the four clues needed to unlock a great treasure. On a sunny/cloudy/rainy/snowy (delete as appropriate) day, they meet up in Cambridge to go punting, share their clues, work out the code for the lock, and share out the treasure. One or more of the mathematicians, however, has decided to lie about their clue so they can steal all the treasure for themselves. At least one mathematician is telling the truth. (If the mathematicians say multiple sentences about their clue, then they are either all true or all false.)
They meet at Cambridge Chauffeur Punts, and head North under Silver Street Bridge. Ben points out a plaque on the bridge with two years written on it:
"My clue," he says, "tells me that the sum of the digits of the code is equal to the sum of the digits of the earlier year on that plaque (the year is 1702). My clue also tells me that at least one of the digits of the code is 7."
The mathematicians next punt under the Mathematical Bridge, gasping in awe at its tangential trusses, then punt along the river under King's College Bridge and past King's College. Katie points to a sign on the King's College lawn near the river:
"See that sign whose initials are PNM?" says Katie. "My clue states that first digit of the code is equal to the number of vowels on that sign (The sign says "Private: No Mooring"). My clue also tells me that at least one of the digits of the code is 1."
They then reach Clare Bridge. Kevin points out the spheres on Clare Bridge:
"My clue," he says, "states that the total number of spheres on both sides of this bridge is a factor of the code (there are 14 spheres). My clue also tells me that at least one of the digits of the code is 2." (Kevin has not noticed that one of the spheres had a wedge missing, so counts that as a whole sphere.)
They continue past Clare College. Just before they reach Garret Hostel Bridge, Sam points out the Jerwood Library and a sign showing the year it was built (it was built in 1998):
"My clue," she says, "says that the largest prime factor of that year appears in the code (in the same way that you might say the number 18 appears in 1018 or 2189). My clue also says that the smallest prime factor of that year appears in the code. My clue also told me that at least one of the digits of the code is 0."
They then punt under Garret Hostel Bridge, turn around between it and Trinity College Bridge, and head back towards Cambridge Chauffeur Punts. Zut alors, the lies confuse them and they can't unlock the treasure. Can you work out who is lying and claim the treasure for yourself?

The solution

The solution to the treasure punt is given below. Once you're ready to see it, click "Show solution".

Show solution

                        
(Click on one of these icons to react to this blog post)

You might also enjoy...

Comments

Comments in green were written by me. Comments in blue were not written by me.
 Add a Comment 


I will only use your email address to reply to your comment (if a reply is needed).

Allowed HTML tags: <br> <a> <small> <b> <i> <s> <sup> <sub> <u> <spoiler> <ul> <ol> <li> <logo>
To prove you are not a spam bot, please type "hparg" backwards in the box below (case sensitive):

Archive

Show me a random blog post
 2024 

Feb 2024

Zines, pt. 2

Jan 2024

Christmas (2023) is over
 2023 
▼ show ▼
 2022 
▼ show ▼
 2021 
▼ show ▼
 2020 
▼ show ▼
 2019 
▼ show ▼
 2018 
▼ show ▼
 2017 
▼ show ▼
 2016 
▼ show ▼
 2015 
▼ show ▼
 2014 
▼ show ▼
 2013 
▼ show ▼
 2012 
▼ show ▼

Tags

radio 4 fonts pi approximation day coins error bars standard deviation curvature inline code mathslogicbot flexagons statistics errors advent calendar zines pi mathsjam manchester science festival asteroids golden spiral captain scarlet quadrilaterals stickers newcastle polynomials computational complexity mean sobolev spaces football inverse matrices final fantasy london matrices draughts php european cup countdown 24 hour maths trigonometry edinburgh programming speed big internet math-off runge's phenomenon matrix of cofactors christmas card menace arithmetic numerical analysis mathsteroids ucl gaussian elimination realhats anscombe's quartet matrix multiplication numbers sound crochet squares fractals datasaurus dozen estimation dragon curves pythagoras gather town machine learning reddit frobel signorini conditions graph theory propositional calculus world cup graphs platonic solids bodmas pascal's triangle rhombicuboctahedron cambridge game of life game show probability sport cross stitch binary chalkdust magazine guest posts games video games triangles hannah fry nine men's morris people maths books talking maths in public logs news light folding paper raspberry pi probability finite element method dinosaurs boundary element methods hexapawn wave scattering matrix of minors interpolation pac-man dates chess misleading statistics pizza cutting palindromes phd bubble bobble royal institution the aperiodical finite group electromagnetic field martin gardner reuleaux polygons london underground noughts and crosses rugby a gamut of games sorting braiding approximation logo hyperbolic surfaces databet manchester recursion royal baby turtles puzzles ternary data simultaneous equations determinants latex preconditioning weather station convergence golden ratio craft matt parker logic python christmas fence posts weak imposition folding tube maps tennis dataset chebyshev wool geometry correlation bempp national lottery map projections stirling numbers data visualisation go crossnumber exponential growth harriss spiral hats plastic ratio tmip gerry anderson javascript oeis live stream accuracy geogebra youtube

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2024