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?
76 kg
76.5 kg
85 kg
Data inadequate
None of these
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 6 of 9.

Ankit saxena said:   1 decade ago
Remember the formula for this type of
new person weight=weight of person tht left+total men*average increased after entry of new men...
Hope it wil help u all

Chithramol ER said:   1 decade ago
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

Radhika said:   1 decade ago
Average of quantities is 22 and average of 36 quantities is 25. What is the average of all the 50 quantities?

Muthu said:   1 decade ago
@Banu nice method.

VIRAT said:   1 decade ago
@Sweta weight of 8 persons is increasing when a new person is coming by replacing a person whose weight is given 65 kg,

Now to know the weight of new person we have add the increased weight in 65 kg simple.

8*2.5 = 20 kgs.

So now the weight of new person is 65+20 kg = 85kg.

Jagat said:   1 decade ago
Thank for this simplication.

Kumar said:   1 decade ago
Here we are replacing the person of 65kg, then how 2. 5kg will effect to replaced person.

Isha said:   1 decade ago
Thanks bhanu your method is so good.

Tinku said:   1 decade ago
@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.

Aamir said:   1 decade ago
A new person's weight is 65 kg and why add early 8 person, where as he is a replaced person.


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