Practice Test: Table Charts - 4 - Mechanical Engineering MCQ

Required difference

    = (No. of students scoring 30 and above marks in Chemistry)

       - (Number of students scoring 30 and above marks in aggregate)

    = 27 - 21

    = 6.

Step 1. Determine the Number of Students in Each Group
Total students: 800.

Secondary Section: 80% of 800
0.80 × 800 = 640 students

Classes 11 and 12: The remaining 20% of 800
0.20 × 800 = 160 students,
Equally divided:
160 ÷ 2 = 80 students each in Class 11 and Class 12.

Step 2.  Find the Missing Value
The table provides the following vegetarian percentages:

Secondary Section: 55%
Class 11: 50%
Class 12: Unknown (let this be x)
Overall: 53%
Calculate the total number of vegetarian students in the school:
Total vegetarians = 0.53 × 800 = 424 students.

Now, compute the number of vegetarians in each group:

Secondary Section: 0.55 × 640 = 352 vegetarians.
Class 11: 0.50 × 80 = 40 vegetarians.
Class 12: x × 80 vegetarians.
The sum of vegetarians from all groups must equal the total number of vegetarians:

(x × 80) + 40 + 352 = 424.

Step 3. Solve for x
80x + 40 + 352 = 424
80x + 392 = 424
80x = 424 - 392 = 32
x = 32 ÷ 80 = 0.4.

Step 4. Convert the Proportion to a Percentage
0.4 × 100% = 40%.

Final Answer:
The percentage of vegetarian students in Class 12 is 40%.

The correct option is C.

It is clear from the above given table of classification of students. Here at least 23 students are eligible that means the marks range from 20-30 is best suitable.