There is a 15 digital card on the desk. Write the numbers 1~ 15 respectively, with the back facing up. If you encounter an odd number, you can win. If you touch an even number, you can clearly win.
(1). This rule is unfair. Because 1- 15 has 8 odd numbers and only 7 even numbers.
(2) Obviously, you may not lose, but the probability of losing is greater than that of Coco.
(3) A fair game is to reduce 14 digital cards. Remove the number 15. Then everyone has the same chance.