The average score of 20 students in a class is 75. If 5 new students join the class and their average score is 80, what is the new average score of all students in the class?

✓ Correct Answer: Option B

Total score for 20 students = 20 * 75 = 1500. Total score for 5 new students = 5 * 80 = 400. New total score = 1500 + 400 = 1900. New total students = 20 + 5 = 25. New average = 1900 / 25 = 76.