Suppose the average weight of 9 persons is 50 kg. The average weight of the first 5 persons is 45 kg, whereas the average weight of the last 5 persons is 55 kg. Then the weight of the 5th person will be
- A45 kg
- B47.5 kg
- C50 kgCorrect
- D52.5 Kg
Explanation
The correct answer is C) 50 kg.
Here's the explanation:
- Calculate the total weight of all 9 persons: 9 persons * 50 kg/person = 450 kg.
- Calculate the total weight of the first 5 persons: 5 persons * 45 kg/person = 225 kg.
- Calculate the total weight of the last 5 persons: 5 persons * 55 kg/person = 275 kg.
When you add the total weight of the first 5 persons and the total weight of the last 5 persons (225 kg + 275 kg = 500 kg), the weight of the 5th person is included twice.
To find the weight of the 5th person, subtract the actual total weight of all 9 persons from this sum: 500 kg - 450 kg = 50 kg.
Analysis of options: A) 45 kg: This is the average of the first 5 persons, not the weight of the 5th person. B) 47.5 kg: This value does not result from the given data. C) 50 kg: This is the calculated weight of the 5th person. D) 52.5 kg: This value does not result from the given data.
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