Latest Capgemini Aptitude Question SOLUTION: The mean of 100 bags was found to be 30. What will be the correct mean if at the time of calculation two bags were wrongly taken as 32 and 12 instead of 23 and 11? A. 29.9 B. 30.5

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(#M40153036) CAPGEMINI Numerical Ability question Keep an EYE

The mean of 100 bags was found to be 30. What will be the correct
mean
if at the time of calculation two bags were wrongly taken as 32 and 12
instead of 23 and 11?
A. 29.9
B. 30.5
C. 34.9
D. 50.8

Asked In Capgemini Dipak Das (8 years ago)

Unsolved Read Solution (13)

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Read Solution (13) :

manoj yadav  (8 years ago)

mean=total sum/total no.
total sum==30*100=3000;
total no.==100
now by mistake take==32,12.....(32+12=44)
sub. with total==3000-44=2956
now use correction==2956+(23+11)=2990
mean=2990/100=29.9 (A)

Is this solution Helpfull? Yes (43) | No (1)  

krishna reddy chemikela  (8 years ago)

100*30=3000
44-34=10
3000-10=2990
2990/100=29.9

Is this solution Helpfull? Yes (18) | No   

Kalyan Das  (8 years ago)

net difference is (23-32)+(11-12)=-10
so, actual mean = 30+(-10)/100=29.9

Is this solution Helpfull? Yes (4) | No   

K.Surya Narayana  (8 years ago)

(98x+32+12)/100=30.
So 98x=2956
Now (98x+23+11)/100=(2956+23+11)/100=29.9
The second way to solve this problem is to think logically. As the weight of the bags reduced, mean should also reduce. The only number which is less than 30 is 29.9 in the options. So ans is 29.9

Is this solution Helpfull? Yes (3) | No   

Unknown  (4 years ago)

Formula
New Average = Old Average - (Changes in calculation/Total number of bags)
Changes in calculation =>
(32+12) - (23+11) = 10
Total number of bags = 100

Therefore,, New Average = 30 - (10/100)

On solving the answer is 29.9

This is simple and easy method

Is this solution Helpfull? Yes (3) | No   

anamika verma  (8 years ago)

sum of the bags=30*100=3000
now it said that (32+12)is wrongly taken instead of (23+11) so new mean will be=3000-44+34/100
2990/100=29.9ans

Is this solution Helpfull? Yes (1) | No (1)  

Vikash kumar  (7 years ago)

shortcut method:
correct answer: 29.9
given avg of 100 bag=30
by mistake he take 32 and 12 instead of 23 and 11
so gap 9+1=10 more in 100 bag so one bag=0.1
so avg is decrease 30-0.1=29.9 is correct answer.

Is this solution Helpfull? Yes (1) | No   

manjinder singh  (8 years ago)

sum = 30*100 =3000
32 and 12 is calculated wrongly as 23 and 11 should be there ,so we will subtract 32 and 21 from the sum which gives 3000 - (32 + 12) =2958
now add 23 and 11 in 2958 which gives 2992 which is sum .
mean =sum /no.
so mean is 2992/100 =29.92 which is a part

Is this solution Helpfull? Yes | No (4)  

vikranth  (7 years ago)

sum=3000;
3000-48=2592
2592+34=2986
2986/100=29.9

Is this solution Helpfull? Yes | No (1)  

sairam  (5 years ago)

2990/100=29.9

Is this solution Helpfull? Yes | No   

tanu  (5 years ago)

As we have given mean and n
therefore we have to take out the sum of all the observations(x)
that is
x = mean × n
x= 30 ×100
x = 3000
now add the correct no. which were misread that is
add 23 and 11
and you will get
3034
now subtract the wrong no. that is
sub 32 and 12 from 3034
that will give you 2990
now it is your new sum of observations
therefore new mean will be
2990/100
=29.9

Is this solution Helpfull? Yes | No   

tanu  (5 years ago)

mean of 100=30
incorrect nos.=32 instead of 23 and 12 instead of 11
-32+23-12+11/100=-10/100=-0.1
30-0.1=29.9

Is this solution Helpfull? Yes | No   

Akanksha Singh  (4 years ago)

X+32+12/100=30
X=2956
2956+23+11/100=29.9

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