1. Peers (from 6th grade, 1 point). Vitya and Masha were born in the same year in June. Find the probability that Vitya is at least one day older than Masha.
Answer: $\frac{29}{60}$.

Solution. $\frac{1}{2} \cdot \frac{900-30}{900}=\frac{29}{60} \approx 0.483$.