Multiple choice

Average weight of a class is 30 kg. 5 students more come whose age is 50 kg and 5 student leave of weight 20 kg. If total number of students in class, initially is 20 then find change percentage in average weight

  1. 10%

  2. 20%

  3. 25%

  4. 30%

  5. 40%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The initial total weight is 20 x 30 = 600 kg. Adding 5 students weighing 50 kg each and removing 5 weighing 20 kg each gives a new total of 750 kg, with 20 students still present. The average rises from 30 kg to 37.5 kg, an increase of 25%.

AI explanation

The total initial weight of the 20 students is 600 kg. The new total weight becomes 600 + 250 - 100 = 750 kg, keeping the number of students at 20. The new average is 750 / 20 = 37.5 kg. The percentage change is calculated as ((37.5 - 30) / 30) * 100, which equals 25%.

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