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Albert.Lang's user avatar
Albert.Lang's user avatar
Albert.Lang
  • Member for 3 years, 7 months
  • Last seen this week
37 votes

Can you tile a 25 x 25 square with a mixture of 2 x 2 squares and 3 x 3 squares?

22 votes
Accepted

Maximum number of pieces on a board

20 votes
Accepted

General attacking chessboard squares

17 votes

Make numbers 1 - 30 using the digits 2, 0, 2, 4

16 votes

Prove that sin(x) ≥ x/2, but without calculus!

15 votes
Accepted

Largest number using 1, 2, 3, 4

14 votes

Find the perimeter (seemingly unsolvable problem)

13 votes
Accepted

Seven robot ants that stay forever on a rod

13 votes
Accepted

1+3 Towers of Hanoi

13 votes

Rock climbing at the Tokyo Olympics

13 votes

849, 352, 768, 493, 527 - Unusual number sequence problem

13 votes
Accepted

Logical puzzle from a math homework for Russian fifth-year school students

12 votes

77-digit number divisible by 7 with seven 7s

12 votes
Accepted

One-sided chess: Self stalemate revisted

12 votes

New record for minimally clued 5x5 Hidato

11 votes

Arithmetic-progression-free sequences

11 votes

Dividing a chocolate frosting cake

10 votes
Accepted

(Almost) all hands on check

10 votes
Accepted

Lap Theory Optimal Betting Game

10 votes
Accepted

A nice robot-control puzzle

10 votes

A balanced banquet

9 votes

12 piece cube packing puzzle

8 votes
Accepted

Making a 3 x 8 grid with tetrominoes

8 votes
Accepted

The game of 42: 10 cards to make 42

7 votes
Accepted

Pawns and a chessboard with no three aligned

7 votes
Accepted

A look at the rooks

7 votes

Two out of a dozen cartons have Easter eggs. Two people try to find one Easter egg carton, each using a different strategy. Who is expected to win?

6 votes
Accepted

What a coincidence or eighteen is not seventeen take two

6 votes

Choosing squares on a square board

6 votes
Accepted

Nondivisibility by 11 puzzle