The following table shows the percentage of marks obtained by seven students in six different subjects in an examination.
|
Student |
Maths |
Chemistry |
Physics |
Geography |
History |
Computer Science |
|
|
Maximum |
Maximum |
Maximum |
Maximum |
Maximum |
Maximum |
|
Ankit |
100 |
80 |
80 |
40 |
70 |
70 |
|
Aman |
90 |
50 |
90 |
60 |
90 |
80 |
|
Ayush |
80 |
65 |
70 |
70 |
80 |
70 |
|
Rohit |
90 |
60 |
80 |
95 |
60 |
60 |
|
Tanvi |
80 |
65 |
65 |
80 |
40 |
60 |
|
Tarun |
70 |
75 |
85 |
77 |
50 |
90 |
|
Muskan |
65 |
35 |
50 |
85 |
80 |
80 |
What are the average marks obtained by all the seven students in Physics? (rounded off to two digits after the decimal)
Answer & explanation
Correct answer: option 4
Total marks of all students in physics = 80% of 120 + 90% of 120 + 70% of 120 + 80% of 120 + 65% of 120 + 85% of 120 + 50% of 120
= \(\frac{4}{5}\) × 120 + \(\frac{9}{10}\) × 120 + \(\frac{7}{10}\) × 120 + \(\frac{4}{5}\) × 120 + \(\frac{13}{20}\) × 120 + \(\frac{17}{20}\) × 120 + \(\frac{1}{2}\) × 120
= 96 + 108 + 84 + 96 + 78 + 102 + 60
= 624
Average marks of all students in Physics = \(\frac{624}{7}\)
= 89.14