In a class of 50 students, the marks of 49 students are given, and their average marks are 70. The teacher then added the marks of the 50th student, and the new average became 71. What were the marks of the 50th student?
Show answer & explanation
Correct answer: C
Explanation
Given:
Average of 49 students = 70
Total students = 50
New average = 71
Total of 49 students = 49 × 70 = 3430
Total of 50 students = 50 × 71 = 3550
Marks of the 50th student = 3550 − 3430 = 120
Marks of the 50th student = 120