Solution: Given that,
Total number of surveyed students `= 25`
Number of students, who had taken all three subjects `= 3`
Number of students, who had taken Physics and Chemistry
` = 4`
Number of students, who had taken Mathematics and
Physics `= 9`
Number of students who had taken Mathematics and
Chemistry `= 5`
Number of students, who had taken Chemistry `= 11`
Number of students, who had taken Physics `= 12`
Number of students, who had taken Mathematics `= 15`
The number of students who had taken only two
subjects `= 6 + 2 + 1 = 9`
Correct Answer is `=>` (C) `9`