Riddles, one at a time
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.
Fence Posts
A straight 15 m fence has a post every 3 m, with one at each end. How many posts are there?
Count the gaps first, then the posts.
Video · Easy
Challenge link
6
15 ÷ 3 = 5 gaps, and 5 gaps need 6 posts.
Crack the Lock
Which 3-digit code opens the lock?
Picture · Hard
Challenge link
738
3 sits in the middle, 8 stays last, 7 goes first.
Old Phone Keys: 4663
Which of the four words types 4663?
Find each digit's letters on the keypad. Only one of the four fits.
Video · Easy
Challenge link
HOME
H is on 4, O on 6, M on 6, E on 3: 4663.
Split 8 Litres
Fewest pours to share it 4 L and 4 L?
Only the 8 L and 5 L jugs can end with 4 L. Use the 3 L jug as a measure.
Video · Genius
Challenge link
7 pours
8→5, 5→3, 3→8, 5→3, 8→5, 5→3, 3→8: 4 L and 4 L.