The Venn diagram shows the number of students who failed in different combinations of English, Hindi, and Maths. We need to find the percentage of students who failed in at least two subjects. This means we need to count the number of students who failed in exactly two subjects or in all three subjects.
From the Venn diagram:
Students who failed in English and Hindi only: 10
Students who failed in Hindi and Maths only: 12
Students who failed in English and Maths only: 12
Students who failed in English, Hindi, and Maths: 5
The number of students who failed in at least two subjects is the sum of those who failed in exactly two subjects and those who failed in all three subjects:
Number of students failed in at least two subjects \( = (\text{English and Hindi only}) + (\text{Hindi and Maths only}) + (\text{English and Maths only}) + (\text{English, Hindi, and Maths}) \)
Number of students failed in at least two subjects \( = 10 + 12 + 12 + 5 = 39 \)
The total number of candidates who appeared in the examination is 500.
The percentage of students who failed in at least two subjects is:
$$ \text{Percentage} = \frac{\text{Number of students failed in at least two subjects}}{\text{Total number of candidates}} \times 100 $$
$$ \text{Percentage} = \frac{39}{500} \times 100 $$
$$ \text{Percentage} = \frac{39}{5} $$
$$ \text{Percentage} = 7.8 $$
Therefore, the percentage of students who failed in at least two subjects is \( 7.8 \).