Aptitude - Average - Discussion
Discussion Forum : Average - General Questions (Q.No. 5)
5.
The average weight of 8 person's increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?
Answer: Option
Explanation:
Total weight increased = (8 x 2.5) kg = 20 kg.
Weight of new person = (65 + 20) kg = 85 kg.
Video Explanation: https://youtu.be/ceg2jvHsiJU
Discussion:
84 comments Page 9 of 9.
Aparna said:
1 decade ago
Oral method:.
When the replaced persons weight was 65 kg then no effect takes place.
But due to him all of thems weight has been increased by 2.5kg.
So,
8*2.5=20.
65+20=85.
When the replaced persons weight was 65 kg then no effect takes place.
But due to him all of thems weight has been increased by 2.5kg.
So,
8*2.5=20.
65+20=85.
Riya said:
1 decade ago
Thank you. I was confused earlier. Your explanation has cleared it all. :).
Anonymous said:
1 decade ago
@ Mariam: Let x be the average weight
First case: Sum of weights of people / 8 people = x
So the sum of weights of people = 8x
Second case: Sum of weights of people / 8 people = x + 2.5
So the sum of weights of people here is 8(x + 2.5) = 8x + 20
So the difference between both sums is essentially the new heavier person that was added which is:
8x + 20 - 8x = 20
So the new guy weights 20kg more than the old guy.
So new guy weights: 65 + 20 = 85kg
First case: Sum of weights of people / 8 people = x
So the sum of weights of people = 8x
Second case: Sum of weights of people / 8 people = x + 2.5
So the sum of weights of people here is 8(x + 2.5) = 8x + 20
So the difference between both sums is essentially the new heavier person that was added which is:
8x + 20 - 8x = 20
So the new guy weights 20kg more than the old guy.
So new guy weights: 65 + 20 = 85kg
Mariam said:
2 decades ago
65 is the weight of only 1 of the 8 persons. Then how can you take it as d weight of all d persons?
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