table charts



The following table gives the percentage of marks obtained by seven students in six different subjects in an examination.
The Numbers in the Brackets give the Maximum Marks in Each Subject.
Student Subject (Max. Marks)
Maths Chemistry Physics Geography History Computer Science
(150) (130) (120) (100) (60) (40)
Ayush 90 50 90 60 70 80
Aman 100 80 80 40 80 70
Sajal 90 60 70 70 90 70
Rohit 80 65 80 80 60 60
Muskan 80 65 85 95 50 90
Tanvi 70 75 65 85 40 60
Tarun 65 35 50 77 80 80

1).
What are the average marks obtained by all the seven students in Physics? (rounded off to two digit after decimal)
A   77.26   
B   89.14   
C   91.37   
D   96.11   
ANS: B - 89.14

Average marks obtained in Physics by all the seven students

 
= 1   x [ (90% of 120) + (80% of 120) + (70% of 120)
7
                + (80% of 120) + (85% of 120) + (65% of 120) + (50% of 120) ]
 
= 1   x [ (90 + 80 + 70 + 80 + 85 + 65 + 50)% of 120 ]
7
 
= 1   x [ 520% of 120 ]
7
 
= 624
7
  = 89.14.

2).
The number of students who obtained 60% and above marks in all subjects is?
A   1   
B   2   
C   3   
D   None   
ANS: B - 2

From the table it is clear that Sajal and Rohit have 60% or more marks in each of the six subjects.

3).
What was the aggregate of marks obtained by Sajal in all the six subjects?
A   409   
B   419   
C   429   
D   449   
ANS: D - 449

Aggregate marks obtained by Sajal
    = [ (90% of 150) + (60% of 130) + (70% of 120) + (70% of 100) + (90% of 60) + (70% of 40) ]
    = [ 135 + 78 + 84 + 70 + 54 + 28 ]
    = 449.

4).
In which subject is the overall percentage the best?
A   Maths   
B   Chemistry   
C   Physics   
D   History   
ANS: A - Maths

The overall percentage for any subject is equal to the average of percentages obtained by all the seven students since the maximum marks for any subject is the same for all the students.
Therefore, overall percentage for:

(i) Maths
= [ 1   x (90 + 100 + 90 + 80 + 80 + 70 + 65) ] %
7
 
= [ 1   x (575) ] %
7
  = 82.14%.

5).
What is the overall percentage of Tarun?
A   52.5%   
B   55%   
C   60%   
D   63%   
ANS: C - 60%

Aggregate marks obtained by Tarun
    = [ (65% of 150) + (35% of 130) + (50% of 120) + ((77% of 100) + (80% of 60) + (80% of 40) ]
    = [ 97.5 + 45.5 + 60 + 77 + 48 + 32 ]
    = 360.
The maximum marks (of all the six subjects)
    = (150 + 130 + 120 + 100 + 60 + 40)
    = 600.

Therefore Overall percentage of Tarun = ( 360 x 100 ) % = 60%.
600