The average weight of 10 persons increases by 2 kg when a new person comes in place of one of them weighing 55 kg. The weight of the new person is:
Answer & explanation
Correct answer: option 3
Let the average of 10 people be x kg
And the weight of the new person be y kg
Sum of 10 people weight is
10× x = 10x kg
When the person is replaced.
10x + y - 55 = 10 × (x + 2)
10x + y - 55 = 10x + 20
y = 55 + 20 = 75 kg
∴ The weight of the new person is 75 kg.