Probability of Preferring Sports or Music

A group of 50 students was surveyed about their preferred extracurricular activities. The results showed that:

• 20 students preferred sports,
• 15 students preferred music,
• 10 students preferred art,
• 5 students preferred both sports and music.

If a student is selected at random from this group, what is the probability that the student prefers either sports or music?