7. Ice Cream (from 6th grade, 2 points.) Anya wants to buy an ice cream that costs 19 rubles. In her pocket, she has two 10-ruble coins, two 5-ruble coins, and one 2-ruble coin. Anya takes out three coins without looking. Find the probability that the coins she took out will be enough to pay for the ice cream.
Solution. There are 5 coins in the pocket, and 3 of them are drawn. Therefore, this experiment has $C_{5}^{3}=10$ equally likely outcomes - the drawn sets of three coins. The event "Anya drew no less than 19 rubles" is favorable in five of them: three outcomes when two ten-ruble coins and one other coin are drawn, and two outcomes when both five-ruble coins and one of the ten-ruble coins are drawn. The required probability is 0.5.

Answer: 0.5.