After a rather difficult puzzle, here is an easy one, should take just a few minutes even for children, please do try! This one is from the site mathsisfun.com.
Four adventurers (Alex, Brook, Chris and Dusty) need to cross a river in a small canoe.
The canoe can only carry 100kg.
Alex weighs 90kg, Brook weighs 80kg, Chris weighs 60kg and Dusty weighs 40 kg, and they have 20kg of supplies.
How do they get across?
As always, please send your answers as comments within the blog (preferred), or send an e-mail to firstname.lastname@example.org. Please do share the puzzle with others if you like, and please also send puzzles that you have come across that you think I can share in this blog.