In a group of 32 students, the average weight was 18.5 kg. When 4 students left the group, the average came down to 15.5 kg. What was the average weight (in kg) of those 4 students?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 39.5.
We know that
Average = Sum of observations/Number of observations
According to the question,
Sum of 32 Students = 18.5 × 32 = 592
Sum When 4 Students Left = 15.5 × 28 = 434
Difference = 592 - 434 = 158
Average = 158/4 = 39.5