The "Treasure Box" interactive link in the "Lucky 52" column of CCTV is a guessing game. The game rules are as follows: among the 20 trademarks, 5 trademarks have prizes, and the remaining 15 trademarks There is no prize. Here we can design a simulation experiment method using substitutes to estimate the probability that the contestant will win the prize for the first time when he flips the trademark: Take 20 balls, 5 red, 15 yellow, and randomly draw with eyes closed. The probability is 25.