Multiple choice

The average weight of $3$ men A, B, and C in a group is $84$kg. Another man D joins the group and the average weight now becomes $80$kg. Another man E, whose weight is $3$ kg more than that of D, replaces A and the average weight of the group (B, C, D and

  1. $70$ kg
  2. $72$ kg
  3. $75$ kg
  4. $80$ kg
Reveal answer Fill a bubble to check yourself
C Correct answer
AI explanation

The total weight of A, B and C is 3 times 84, which is 252 kg. When D joins, the total weight of the 4 men becomes 4 times 80, or 320 kg, making the weight of D equal to 320 minus 252, which is 68 kg. Since E weighs 3 kg more than D, the weight of E is 71 kg. The total weight of B, C, D and E is 4 times 79, or 316 kg, so the weight of A is the difference between the total weight of A, B, C, D and the total weight of B, C, D, E. The weight of A is 320 minus 316, which is 75 kg.

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