Riddles, one at a time
How Many Routes: 2 × 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.
6
Add the ways from the left and from below: 3 + 3 = 6.
Fewest Tokens: Pay 6
Which tokens pay 6 with the fewest tokens?
Biggest first is not always fewest. Try every pair.
3 + 3
Just 2 tokens. Biggest first, 4 + 1 + 1, needs 3.
How Many Routes: Pass the Lantern
Moving only right or up, how many routes from start to the gem pass the lantern?
Count the ways to the lantern, then the ways from it to the gem, and multiply.
36
6 ways to the lantern, then 6 ways on: 6 × 6 = 36.
The Lamp and the Wall
Which shadow appears on the wall?
C
Each row's tallest stack sets the shadow.
Mirror Clock: 13:31
How many minutes until the clock shows the next mirror time?
Try the next hour: 14:??
70 minutes
The next mirror time is 14:41, 70 minutes later.
Move One Rod
Move exactly one rod. What is the true equation?
9 − 8 = 1
The top rod of the 7 turns the 3 into a 9.