Riddles, one at a time
Dim or Bright
What number does the last row show?
First find each lamp's value: the top row gives the left lamp.
22
The top 3 rows give lamp values 9, 3 and 1. Bright counts double: 18 + 3 + 1 = 22.
Two Candles: 32 cm and 22 cm
After how many hours are they the same height?
Find the gap at the start, then how much it closes each hour.
5 hours
After 5 h: A is 32 − 20 = 12 cm, B is 22 − 10 = 12 cm.
One Piece Fits
Pieces may turn but never flip over. Which piece fills the hole?
PIECE C
Turn C a quarter turn: it drops right in.
Mirror Odometer: 15951
How many more km until the next mirror number?
The middle digit is already 9, so it cannot go up. What has to change instead?
110 km
The next mirror number is 16061: 16061 − 15951 = 110.
Fewest Tokens: Pay 24
Which tokens pay 24 with the fewest tokens?
Biggest first is not always fewest. A token can be used many times.
6 + 6 + 6 + 6
Just 4 tokens. Biggest first, 15 + 6 + 1 + 1 + 1, needs 5.
Join the Dots
Join 3, 6, 9... in order. What appears?
C LANTERN
3 to 45 traces a lantern; the rest are decoys.