Study the following table and answer the questions.Classification of 100…
2024
Study the following table and answer the questions.Classification of 100 Students Based on the Marks Obtained by them in Physics and Chemistry in an Examination.
The percentage of number of students getting at least 60% marks in Chemistry over those getting at least 40% marks in aggregate, is approximately?
- A.
21%
- B.
27%
- C.
29%
- D.
31%
Attempted by 1 students.
Show answer & explanation
Correct answer: C
Concept
In a cumulative "X and above" frequency table, first convert the required percentage of marks into the actual mark threshold using the full marks, then read off the matching cumulative count from the correct column. A percentage of one group relative to another group is (count satisfying condition A) divided by (count satisfying condition B), multiplied by 100.
Application
Full marks = 50, so "at least 60% marks" = 30 marks and "at least 40% marks" = 20 marks.
Number of students scoring at least 60% in Chemistry = count in the "30 and above" Chemistry column = 21.
Number of students scoring at least 40% in aggregate = count in the "20 and above" Aggregate column = 73.
Required percentage = (21 ÷ 73) × 100 = 28.77%, which is closest to 29%.
Cross-check
73 × 0.29 ≈ 21.2, close to the actual count of 21, confirming that 29% is the best-supported rounded value among the given options.