Favourite puzzles - 13. How old is Alice?

Notes from the underground

barang dot sg

Updated 28 January 2023

Favourite puzzles

41. The watermelon

40. Multiple choice

39. Odd one out

38. Water jugs and burning ropes

37. Dominoes on a chessboard

36. Three white hats

35. Four daughters

34. The war veteran

33. Elementary logic

32. Logical fatalism

31. Bertrand’s paradox

30. The ship of Theseus

29. Simpson’s paradox

27. The missing dollar

26. The two envelope problem

24. The wheel and the hub

23. Every natural number can be unambiguously described in fourteen words or less

22. The bottle and the cork

21. Proof that unicorns exist

20. The three marbles

19. Chess position

18. Ten statements

17. What position?

16. How many handshakes?

15. Roll a coin

13. How old is Alice?

12. Knockout tournament

11. The gambler’s-fallacy fallacy

10. The biased coin

9. All horses are of the same colour

8. The couple on the bus

7. A million dots

4. Why does a mirror?

3. The tribe that favours boys

2. The water lily

1. Matching socks

13. How old is Alice?

Girl

Alice is twelve years old plus half her age. How old is Alice?

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