Consider the Diagram.
500 Candidates appeared in an Examination comprising test in English, Hindi and Maths. The Diagram gives number of students who failed in different tests. What is the % percentage of student who failed at least two subjects?

7.8%

Numbers of candidates who failed in at least two subjects = (12 + 12 + 10 + 5) = 39

When the number of people surveyed = 500

= 39 / 500 × 100 = 7.8%