Concept of “Average” [“औसत”]-06

Question: The average weight of 8 persons increases by 1.5 Kg., if a person weighing 65 Kg. is replaced by a new person, what could be the weight of the new person? [8 लोगों का औसत वजन 1.5 किलोग्राम बढ़ जाता है, यदि उनमें से एक व्यक्ति, जो 65 किलोग्राम का है, उसकी जगह पर एक नया व्यक्ति आ जाता है. बताइए कि नए व्यक्ति का वजन क्या है? [Ans. (b) 77 kg]

(a) 76 Kg  (b) 77 Kg (c) 76.5 Kg (d) Data Inadequate (e) None of these

Detailed explanation:

Concept: Definition

Average: “Average of any set of items is the ‘value’, which is obtained by dividing all the items among them - equally.” In other words, “If all the items of a set is distributed equally among them, then what each will get – that each value is the ‘average’.”   

Solution: Given that the average weight of 8 persons increases by 1.5 kg. It means weight of each persons increase by 1.5 kg. So, the total increase in weight is 1.5× 8 kg = 12 kg. The new person should have weight, 12 kg more than the person having weight of 65 kg, and who is to be replaced.

Therefore, the weight of new person = (65 + 12) kg = 77 kg Ans.