Riddles, one at a time
Inside the Loop: The Trapped Gem
Which gem is INSIDE the loop?
Count wall crossings on the way to the edge: odd means inside.
Video · Hard
Challenge link
B
Gem B is inside; A, C and D sit in pockets that open to the outside.
Two Glass Cards
Slide the two glass cards together. Which number appears?
Imagine the strokes of both cards on one card.
Video · Easy
Challenge link
48
Card A's strokes fill the gaps on card B: 4 and 8.
Fewest Tokens: Pay 11
Which tokens pay 11 with the fewest tokens?
Biggest first is not always fewest. Try every pair.
Video · Hard
Challenge link
5 + 6
Just 2 tokens. Biggest first, 9 + 1 + 1, needs 3.
How Many Routes: 3 × 2 Grid
Moving only right or up, how many different routes lead from start to the gem?
Each corner's count is the count to its left plus the count below it.
Video · Medium
Challenge link
10
The two corners next to the gem can be reached in 6 and 4 ways: 6 + 4 = 10.
