Multiple choice

The average weight of a group of 6 people is decreased by 2 kg when a person weighing 90 kg is replaced by a new person. If this new person is again replaced by another person weighing 30 kg less then the new person. What is the total change in the average weight of the group?

  1. 5 kg

  2. 7 kg

  3. 8 kg

  4. Cannot be determined

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let original average = A. First replacement reduces average by 2 kg, so new person weighs 90 - 12 = 78 kg (since 6 people × 2 kg = 12 kg total reduction). This new person (78 kg) is replaced by someone 30 kg lighter: 78 - 30 = 48 kg. Total reduction now = 90 - 48 = 42 kg. Average reduction = 42 ÷ 6 = 7 kg total change.

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