1, the rule of calculating 24 points
Randomly draw four cards from a deck of playing cards with no king, where A is 1, J is 1 1, Q is 12, and K is 13. 24 can only be calculated by addition, subtraction, multiplication and division, but not by power, root and factorial. There are also antagonistic double kills.
2. Count 24. 1 * * *, how many questions are there?
Regardless of the color and order of the cards, the problem of calculating 24 points can correspond to the combination of 16 and 4, so the problem of calculating 24 points is 1820. Through computer programming, we know that there are 1362 solutions, that is, 74.84% of the problems have solutions.
3. Only add and subtract.
One of the most basic ways to calculate 24 points is to use only addition and subtraction, which can be divided into three situations:
1, all together, such as A2 10J, A788, 5568, etc. This seemingly simple method is actually the only solution to many problems, which is often easily overlooked.
2. The sum of three numbers minus the fourth number, such as 388J, 45 10K, 58 10J, etc.
3. Subtract the sum of two numbers from the sum of the other two numbers. In this case, there is only one problem, that is AAKK.
Summary: whether a problem can only be solved by addition and subtraction can be quickly judged by parity, that is, only odd or even problems can not be solved by addition and subtraction alone.
4. Basic formula
These three sentences, 3824, 4624, two times twelve equals twenty-four, can be regarded as a 24-point basic formula, and nearly half of the problems that can be solved can be summarized in these three sentences, which is our top priority.
Introduction to 24 points:
Chess puzzle game requires that the result of four numbers is equal to twenty-four. Let's play together! This game is easier to play with playing cards. Take a deck of cards, draw out the queen and queen (you can also take J/Q/K/ King and Queen for the first time), and leave 40 cards (1 ~ 10 instead of A).
Randomly draw 4 cards (called cards), and use addition, subtraction, multiplication and division (parentheses can be added, and advanced players can also use power square root and factorial operations) to calculate the number on the card face as 24. Each card can only be used once. If the cards drawn are 3, 8, 8 and 9, the formula is (9-8)×8×3=24.