Multiple choice

The average weight of 50 students is 16 kg. The average weight of the first 24 students is 14.5 kg and that of the last 25 students is 17 kg. Find the weight of the twenty-fifth student.

  1. 24 kg

  2. 25 kg

  3. 27 kg

  4. 28 kg

  5. 30 kg

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total weight of 50 = 50 * 16 = 800. Sum of first 24 = 24 * 14.5 = 348. Sum of last 25 = 25 * 17 = 425. Weight of 25th student = 800 - (348 + 425) = 800 - 773 = 27 kg.

AI explanation

The total weight of all 50 students is 50 multiplied by 16, which equals 800 kg. The total weight of the first 24 students is 24 multiplied by 14.5, equaling 348 kg, and the total weight of the last 25 students is 25 multiplied by 17, equaling 425 kg. The weight of the twenty-fifth student is the overall total minus these two groups, giving 800 minus 348 minus 425, which equals 27 kg.