What is the average marks of all the students if the average marks of three batches of 55, 60, and 45 students is 50, 55, and 60, respectively?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 54.68.
Batch 1: 55 students, average = 50
Batch 2: 60 students, average = 55
Batch 3: 45 students, average = 60
Total marks for each batch
Batch 1: 55 × 50 = 2750
Batch 2: 60 × 55 = 3300
Batch 3: 45 × 60 = 2700
Total marks = 2750 + 3300 + 2700 = 8750
Total students = 55 + 60 + 45 = 160
Average = 8750/160 = 54.6875