Aptitude - Average - Discussion
Discussion Forum : Average - General Questions (Q.No. 12)
12.
The average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg. Find the average weights of all the boys in the class.
Answer: Option
Explanation:
| Required average |
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| = 48.55 |
Discussion:
31 comments Page 1 of 4.
Farhin Rizvi said:
9 years ago
As given, the average weight of 16 boys in a class = 50.25kg.
Thereby,we can write it as x1 + x2,....x16/16 = 50.25,
= x1 + x2 +.....+ x16 = 50.25 * 16 = 804.
For remaining 8 boys x1 + x2 +....+ x8/8 = 45.15,
= x1 + x2 + x3 + ........ + x8 = 45.15 * 8 = 361.2.
Thereby total number of boys = 16 + 8 = 24.
And total weight = 804 + 361.2 = 1165.2.
Average = 1165.2/24 = 48.55.
Thereby,we can write it as x1 + x2,....x16/16 = 50.25,
= x1 + x2 +.....+ x16 = 50.25 * 16 = 804.
For remaining 8 boys x1 + x2 +....+ x8/8 = 45.15,
= x1 + x2 + x3 + ........ + x8 = 45.15 * 8 = 361.2.
Thereby total number of boys = 16 + 8 = 24.
And total weight = 804 + 361.2 = 1165.2.
Average = 1165.2/24 = 48.55.
Jithu said:
1 decade ago
See @hema
Avg=total/no
avg_weight=total_weight/no_student
here 16 boys's avg =50.25
let us take x be total
Avg=x/no
ie,50.25=x/16
so
x=50.16*25
x=804------(1)
let take y be total
then
Avg=y/no
ie,45.15=y/8
So y= 45.15*8
y==361.20--------(2)
Total_number of students is=16+8=24
So all weight=x+y
i.e,804+361.20=1165.20
avg=total/no
therefore avg=1165.20/24
Avg=48.55
Avg=total/no
avg_weight=total_weight/no_student
here 16 boys's avg =50.25
let us take x be total
Avg=x/no
ie,50.25=x/16
so
x=50.16*25
x=804------(1)
let take y be total
then
Avg=y/no
ie,45.15=y/8
So y= 45.15*8
y==361.20--------(2)
Total_number of students is=16+8=24
So all weight=x+y
i.e,804+361.20=1165.20
avg=total/no
therefore avg=1165.20/24
Avg=48.55
Ishwar said:
5 years ago
The avg weight of 16 boys is 50.25, then the sum of wt of all 16 boys is 50.25 * 16 = 804.
The avg wt of remaining 8 boys is 45.15, then the sum of wt of all 8 boys is 45.15 * 8 = 361.2 .
Total boys in a class is 804+361.2 = 1165.2.
And the whole avg is 1165.2/(16+8) = 48.55.
The avg wt of remaining 8 boys is 45.15, then the sum of wt of all 8 boys is 45.15 * 8 = 361.2 .
Total boys in a class is 804+361.2 = 1165.2.
And the whole avg is 1165.2/(16+8) = 48.55.
(5)
KIRAN KUMAR said:
9 years ago
This is a weighted average problem. In weighted average problem the value of the actual weights is not required. The ratio of the weights also will give you the same answer. Thus instead of 8 and 16 we can take the ratios of 8 and 16. i.e. 2 and 1 as our weights.
Nitin said:
9 years ago
Can be simply done by allegation rule.
50.25 45.15
\ /
\ /
X
/ \
/ \
2 1
NOW, (X - 45.25)/(50.25 - X) = 2/1 i.e. x = 48.55.
50.25 45.15
\ /
\ /
X
/ \
/ \
2 1
NOW, (X - 45.25)/(50.25 - X) = 2/1 i.e. x = 48.55.
(1)
Swapnil said:
1 decade ago
16 * 50.25= 804 (total wt of 16 boys)
8 * 45.15= 361.2 (total wt remaining 8 boys)
_____________________
24 = 1165.2 (total wt of all boys)
= 1165.2/24
=48.55 (Average wt of all boys)
8 * 45.15= 361.2 (total wt remaining 8 boys)
_____________________
24 = 1165.2 (total wt of all boys)
= 1165.2/24
=48.55 (Average wt of all boys)
M.V.KRISHNA/PALVONCHA said:
1 decade ago
Avg. of 16 boys= 50.25,
weight of 16 boys=(50.25*16)=804,
avg. of 8 boys= 45.15,
weight of 8 boys=(45.15*8)=361.2,
total no. boys=24,
total weight of the boys=1165.2.
avg. weight of 24 boys=(1165.2/24)
=48.55.
weight of 16 boys=(50.25*16)=804,
avg. of 8 boys= 45.15,
weight of 8 boys=(45.15*8)=361.2,
total no. boys=24,
total weight of the boys=1165.2.
avg. weight of 24 boys=(1165.2/24)
=48.55.
Sunita said:
8 years ago
Let's take X=50.25 and Y=45.15.
It's given avg of 16 mem is 50.25 so X= 16*50.25 = 804 and in the same manner 8 member Y= 45.15*8 = 361.2.
The total members are 24 therefore;
AVERAGE = (804+361.2)/24 = 48.55.
It's given avg of 16 mem is 50.25 so X= 16*50.25 = 804 and in the same manner 8 member Y= 45.15*8 = 361.2.
The total members are 24 therefore;
AVERAGE = (804+361.2)/24 = 48.55.
Shubham j said:
7 years ago
16 boys having avg. wt. of : 50.25, i.e 50.25 * 16 = 804.
8 boys having avg. wt. of : 45.15 i.e 45.15 * 8 = 361.2.
804+361.2=1165.2.
1165.2/24 = 48.55 (24 is total boys).
8 boys having avg. wt. of : 45.15 i.e 45.15 * 8 = 361.2.
804+361.2=1165.2.
1165.2/24 = 48.55 (24 is total boys).
(1)
Muneer.s said:
1 decade ago
16 boys total weight= 50.25*16= 804kg
8 boys total weight= 45.15*8= 361.2
Total weight of all boys= 804+361.2 =1165.2
Avg weight of all boys= 1165.2/24= 48.55
8 boys total weight= 45.15*8= 361.2
Total weight of all boys= 804+361.2 =1165.2
Avg weight of all boys= 1165.2/24= 48.55
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