The average weight of 20 people is 75 kg. The average weight of 10 people out of them is 70 kg. The average weight of 5 people out of the remaining people is 75 kgs. Find the average weight of 5 people remaining in the end.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 85 kgs.
We know that,
Average = Sum of observations/Number of observations
Now,
The sum of the weight of 20 people = 20 × 75 = 1500 kg
The sum of the weight of 10 people = 10 × 70 = 700 kg
The sum of the weight of 5 people = 5 × 75 = 375 kg
The weight of remaining 5 people = 1500 - (700 + 375)
⇒ 1500 - 1075 = 425
Average weight of remaining 5 people = 425/5 = 85 kg