OG详解-OG4 数学2 Q13

The correct answer is310​​. It’s given that there are a total of  100  tiles of equal area, which is the total number of possible outcomes. According to the table, there are total of 30 red tiles. The probability of an event occurring is the ratio of the number of favorable outcomes to the total number of possible outcomes.  By definition, the probability of selecting a red tile is given by 3100​​, or 310​​. Note that 3/10 and  3 are examples of ways to enter a correct answer.