The average weight of 10 students increases by 2 kg if a student whose weight is 50 kg is replaced by a new student. What is the weight of the new student (in kg)?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 70
If the average of 10 students rises by 2 kg, the total weight rises by \(10\times2=20\) kg. Only one student has changed, so the newcomer must weigh 20 kg more than the student who left.
Rise in the total \(=10\times2=20\) kg
Weight of the new student \(=50+20=70\) kg