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 7 of 9.
Vinoth M said:
1 decade ago
When a new person weight is added to 8 peoples weight each person weight is increased by 2.5%
Then weight increased is 8*2.5=20
So the new person age is 65+20=85
Then weight increased is 8*2.5=20
So the new person age is 65+20=85
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
Manoj Kumar said:
1 decade ago
Thanks for your support guys. Will post more useful information in future.
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?
Sagar said:
9 years ago
Is there any shortcut method to solve this problem? Please help me.
Anil Kumar Basam said:
9 years ago
Total 9 person's average weight = 65 -> So, 65*9 = 585.
Every person comes in the place increases 2.5 -> So, 65 - 2.5 = 62.5.
8 persons average weight = 62.5.
Sum of the elements = average*total numberof elements.
=> 62.5*8 =500.
Sum of 9 persons - sum of 8 persons = 585 - 500= 85.
New person weight = 85kg.
Every person comes in the place increases 2.5 -> So, 65 - 2.5 = 62.5.
8 persons average weight = 62.5.
Sum of the elements = average*total numberof elements.
=> 62.5*8 =500.
Sum of 9 persons - sum of 8 persons = 585 - 500= 85.
New person weight = 85kg.
Naveen said:
9 years ago
The average of marks obtained in 120 students was 35. If the average of passed candidates was 39 and that of failed candidates is 15, the no of candidates who passed the examination is?
Nandini said:
10 years ago
Hai friends.
Can any one explain me why we add 20+65? Why not 20-65?
Can any one explain me why we add 20+65? Why not 20-65?
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