The average weight of 12 persons increases by 3.5 kg when a new person comes in place of one of them weighing 58 kg. The weight of the new person is:

100 kg 16 kg 70 kg 42 kg

100 kg

Lets assume weight of new man be x Sum of weight before replacement be y As average weight is increased by 3.5 kg ⇒ \(\frac{y - 56 + x}{12}\) = \(\frac{y}{12}\) + 3.5 ⇒ y - 58 + x = y + 42 ⇒ x = 100 kg