Understanding Student Performance Analysis from Table

The question asks us to determine the number of students whose overall percentage in the examination is 80% or above, based on the provided table of marks.

The table shows the marks obtained by six students (A, B, C, D, E, F) in four different subjects: SST, Physics, Chemistry, and Maths. The maximum marks in each subject are 100.

Calculating Overall Percentage

To find the overall percentage for each student, we first need to calculate the total marks obtained by the student across all four subjects. Since the maximum marks for each subject is 100, the total maximum marks for the four subjects is $100 \times 4 = 400$.

The overall percentage is calculated using the formula:

Overall Percentage $= \left( \frac{\text{Total Marks Obtained}}{\text{Total Maximum Marks}} \right) \times 100$

In this case, Total Maximum Marks = 400. So, the formula becomes:

Overall Percentage $= \left( \frac{\text{Total Marks Obtained}}{400} \right) \times 100$

Calculating Overall Percentage for Each Student

Let's calculate the total marks and overall percentage for each student:

• Student A: Total Marks = $92 + 90 + 90 + 80 = 352$. Overall Percentage = $\left( \frac{352}{400} \right) \times 100 = 0.88 \times 100 = 88\%$.
• Student B: Total Marks = $90 + 80 + 85 + 85 = 340$. Overall Percentage = $\left( \frac{340}{400} \right) \times 100 = 0.85 \times 100 = 85\%$.
• Student C: Total Marks = $80 + 80 + 65 + 70 = 295$. Overall Percentage = $\left( \frac{295}{400} \right) \times 100 = 0.7375 \times 100 = 73.75\%$.
• Student D: Total Marks = $85 + 80 + 82 + 75 = 322$. Overall Percentage = $\left( \frac{322}{400} \right) \times 100 = 0.805 \times 100 = 80.5\%$.
• Student E: Total Marks = $80 + 75 + 75 + 85 = 315$. Overall Percentage = $\left( \frac{315}{400} \right) \times 100 = 0.7875 \times 100 = 78.75\%$.
• Student F: Total Marks = $90 + 90 + 90 + 85 = 355$. Overall Percentage = $\left( \frac{355}{400} \right) \times 100 = 0.8875 \times 100 = 88.75\%$.

Identifying Students with 80% and Above Overall Percentage

Now we check which students have an overall percentage of 80% or above:

• Student A: 88% ( $\ge 80\%$, Yes)
• Student B: 85% ( $\ge 80\%$, Yes)
• Student C: 73.75% ( $\ge 80\%$, No)
• Student D: 80.5% ( $\ge 80\%$, Yes)
• Student E: 78.75% ( $\ge 80\%$, No)
• Student F: 88.75% ( $\ge 80\%$, Yes)

The students with an overall percentage of 80% and above are Student A, Student B, Student D, and Student F.

Counting the Students

There are 4 students (A, B, D, F) whose overall percentage is 80% or above.

Conclusion

The number of students whose overall percentage obtained is 80% and above is 4.

Revision Table: Student Marks and Overall Percentage

Additional Information on Percentage Calculation

Percentage is a way to express a number as a fraction of 100. It is widely used in various contexts, including academics, finance, and statistics.

• To calculate the percentage of a value relative to a total value, use the formula: $\left( \frac{\text{Value}}{\text{Total Value}} \right) \times 100$.
• In academic results, overall percentage gives a single metric to understand a student's performance across multiple subjects relative to the maximum possible score.
• Understanding percentages helps in comparing different scores or quantities on a standard scale of 100.

This type of data analysis from tables is common in exams and helps in evaluating and comparing performance metrics.