The average weight of 12 students and two teachers is 55 kg. When one teacher weighing 68 kg is included in the group, then the average weight of the group (in kg) is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 56.
Average weight of 12 students + 2 teachers = 55 kg
Total people = 14
Total weight = 14 × 55 = 770 kg
Now, one teacher weighing 68 kg is included (so, the total people = 15):
New total weight = 770 + 68 = 838 kg
New average weight = 838 ÷ 15 = 55.87 or 56 kg