## The Hardest Make 24 Puzzles

Make 24 is a traditional math game with simple rule – given 4 numbers, you are asked to make 24 with addition +, subtraction -, multiplication * and division /. Each number should be used once and only once. For example, (3, 7, 2, 1) --> 3 * (7 + 2 - 1) = 24. Most Make 24 puzzles are easy but a few are extremely hard. This post collects some of the hardest puzzles and discuss them in 3 types....