Aptitude - Average - Discussion
Discussion Forum : Average - General Questions (Q.No. 14)
14.
If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:
Answer: Option
Explanation:
| Required average |
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| = 54.68 |
Discussion:
22 comments Page 2 of 3.
Dr.R.Baskaran said:
8 years ago
55: 60:45 = 11:12:9.
Choose the origin (assumed average) as 55.
The sum of the deviations = 11x(-5) + 9x5 = -10.
Average = 55 - 10/(11 + 12 + 9) = 55 - 10/32.
You have to subtract about 1/3 which is nearly 0.33. The answer is 54.68.
Choose the origin (assumed average) as 55.
The sum of the deviations = 11x(-5) + 9x5 = -10.
Average = 55 - 10/(11 + 12 + 9) = 55 - 10/32.
You have to subtract about 1/3 which is nearly 0.33. The answer is 54.68.
(1)
Gourav Singh said:
1 month ago
Given
Batch 1: 55 students, average = 50
Batch 2: 60 students, average = 55
Batch 3: 45 students, average = 60
Step 1: Find total marks of each batch
Batch 1 total = 55 × 50 = 2750
Batch 2 total = 60 × 55 = 3300.
Batch 3 total = 45 × 60 = 2700
Step 2: Find the overall total marks and students.
Total marks = 2750 + 3300 + 2700 = 8750.
Total students = 55 + 60 + 45 = 160.
Step 3: Find the overall average.
Average.
= 8750/ 160.
= 54.6875.
Batch 1: 55 students, average = 50
Batch 2: 60 students, average = 55
Batch 3: 45 students, average = 60
Step 1: Find total marks of each batch
Batch 1 total = 55 × 50 = 2750
Batch 2 total = 60 × 55 = 3300.
Batch 3 total = 45 × 60 = 2700
Step 2: Find the overall total marks and students.
Total marks = 2750 + 3300 + 2700 = 8750.
Total students = 55 + 60 + 45 = 160.
Step 3: Find the overall average.
Average.
= 8750/ 160.
= 54.6875.
Muneer.s said:
1 decade ago
Total marks of first batch(55) is= 55*50=2750
Total marks of second batch (60)is= 60*55=3300
Total marks of third batch(45)= 45*60=2700
Total marks of second batch= 2750+3300+2700 = 8750
Total number of Students= 55+60+45 =160
Avg= 8750/160= 54.68
Total marks of second batch (60)is= 60*55=3300
Total marks of third batch(45)= 45*60=2700
Total marks of second batch= 2750+3300+2700 = 8750
Total number of Students= 55+60+45 =160
Avg= 8750/160= 54.68
Srid said:
5 years ago
Let T be total marks if all pupil, N be no of students, A be the average mark.
Case 1( when marks were entered correctly ie 63).
T/N=A.
Case 2(83)
(T+20)/N=A+0.5.
Subtract both equations.
20/N = 0.5.
N= 40.
Case 1( when marks were entered correctly ie 63).
T/N=A.
Case 2(83)
(T+20)/N=A+0.5.
Subtract both equations.
20/N = 0.5.
N= 40.
Pranay RK said:
8 years ago
It is clearly written 55, 60, 45 are total no of students. (i.e) 160 total student.
Whereas average marks of the student are 50, 55, 60.
Whereas average marks of the student are 50, 55, 60.
Swa said:
8 years ago
Thank you @Sadhya.
Keshav singh said:
8 years ago
Thanks @S. Balasubramaniam.
Bhavik oza said:
9 years ago
Average marks are asked. So how can 160 come in the denominator? If you keep 160 then you will get average students as your answer.
Riyaz said:
10 years ago
Thank you all who has given suggestions while solving the problems.
Vicky said:
10 years ago
Thanks, @Balasubramaniam.
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