Building Bridges Chuck’s ranch is 16km north of a narrow straight river flowing west to east. His cousin Dwayne has a ranch 72km south and 30km east of...
Family Street George and Martha live in Millipede Avenue, a road with 1,000 houses numbered from 1 to 1,000. Their five daughters and their families will also...
New Towns Three new towns (A, B and C) were being built, with straight roads joining them. Each road was a whole number of miles in length, with AB the same...
A Dish Best Served Cold King Otto’s birthday cake was a giant mousse. Its tiers were two concentric regular octagons. The upper tier’s span equalled the lower...
Pin-up Over the years I have used seven different PINs. The first consisted of a four-digit number (the first digit not being zero), and thereafter each new...
Things with Scales and Things to Scale with Rummaging through a cupboard I came across an old Snakes and Ladders set. The ladders (label them A to E) went...
Roaming Bull Farmer Quentin keeps his prize bull in a circular field of diameter 50m. To improve the layout, he decides to switch to a square field with side...
Knights and Knaves On my travels, I came across a group of some knights (always truthful) and some knaves (always lying). At first, I couldn’t tell which were...
Challenging Grandson My grandson likes making puzzles; his most recent one started with a four-digit number with all the digits different. He added up all the...
Round the Table I recently attended a celebration with fewer than 100 family and friends. We sat round a large oval table with one seat for each person. I...
ADVERTISEMENT
