The average weight of 18 boys in a group is 35 kg.If four new boys of weights 20 kg, 22 kg 26 kg and 28 kg are added to the group, then what is the average weight of the newly formed group?

33 kg

Sum of weight of 18 boys = 18 × 35 = 630 kg

Sum of all 22 boys = 630 + 20 + 22 + 26 + 28 = 726 kg 

New average weight = \(\frac{726}{22}\) = 33 kg