A certain number of students from school X appeared in an examination and 30% students failed. 150% more students than those from school X, appeared in the same examination from school Y. If 80% of the total number of students who appeared from both the schools passed, then what is the percentage of students who failed from Y?

Number of students failed in school X = 30% Number of students in school Y = 150% more than number of students in school X Students passed in both schools = 80% Let number of students in school X be 100x. Number of failed students in school X = 30% of 100x = 30x Number of passes students in school Y = (100x – 30x) = 70x Number of students in school Y = 100x + 150% of 100x = 100x + 150x = 250x Total number of students in school X and school Y = 100x + 250x = 350x Number of passes students in both schools = 80% of 350x = 280x So, number of passed students in school Y = 280x – 70x = 210x Number of failed students in school Y = 250x – 210x = 40x Percentage of failed students in school Y = (40x/250x) × 100% = 16% ∴ The percentage of students who failed from school Y is 16%.