"Nothing in life is to be feared, it is only to be understood."
- Marie Curie
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?
65 is the weight of only 1 of the 8 persons.....thn how can u take it as d weight of all d persons????
Anonymous said:
(Wed, Oct 27, 2010 09:55:44 AM)
@ 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
Riya said:
(Mon, Nov 8, 2010 07:49:18 AM)
Thank you. I was confused earlier. Your explanation has cleared it all. :).
Aparna said:
(Wed, Dec 29, 2010 04:14:25 AM)
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.
Vinoth M said:
(Thu, Feb 17, 2011 07:23:19 AM)
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
Aamir said:
(Sun, Jul 24, 2011 05:31:50 PM)
A new person's weight is 65 kg and why add early 8 person, where as he is a replaced person.
Tinku said:
(Fri, Aug 5, 2011 11:24:23 PM)
@Aamir
It is not weight of the new person. It is weight of which person who is replace from the new person.
Let weight of new person is = x.
Replace person weight=65kg.
Total person=8.
Let total weight 8 person is W.
Before replace of a person.
W/8=a.
Here the a is the average.
Now replace a person which weight is 65kg.
(x+W-65)/8=a+2.5.
Put w=8a from above eqn.
Wet get x=85kg.
Bhanu said:
(Fri, Aug 12, 2011 05:38:24 PM)
Hai Friends.
Try this method.
New person weight =Replaced person weight+ (no. Of persons*increased weight).
Replaced person weight =65.
No. Of persons =8.
Increased weight =2.5.
These all values are replaced in the formula, then we get the answer "85".
Isha said:
(Sat, Aug 20, 2011 01:32:00 PM)
Thanks bhanu your method is so good.
Kumar said:
(Thu, Aug 25, 2011 07:11:54 AM)
Here we are replacing the person of 65kg, then how 2. 5kg will effect to replaced person.
Jagat said:
(Sat, Oct 8, 2011 09:32:37 AM)
Thank for this simplication.
Shiya said:
(Tue, Nov 15, 2011 12:57:11 PM)
@kumar
Hi kumar in the problem they are saying that it wil be effect 2.5 kg that means may be new person weight will be greater than other remaining 7 persons. In this situation they may be effect rite.
Radhika said:
(Wed, Nov 23, 2011 10:05:57 PM)
Average of quantities is 22 and average of 36 quantities is 25. What is the average of all the 50 quantities?
Muthu said:
(Thu, Nov 24, 2011 07:18:40 AM)
@Banu nice method.
Chithramol Er said:
(Tue, Dec 20, 2011 11:22:57 AM)
New person weight =Replaced person weight+ (no. Of persons*increased weight).
Replaced person weight =65.
No. Of persons =8.
Increased weight =2.5.
These all values are replaced in the formula, then we get the answer as 85
