Probability of Preferring Apples or Bananas

A group of students surveyed their favorite types of fruit. The results showed:

• 12 students preferred apples
• 8 students preferred bananas
• 5 students preferred oranges
• 3 students preferred grapes

What is the probability that a randomly chosen student from this group prefers either apples or bananas? Express your answer as a fraction in simplest form.