The total number of students in a school is 1400, out of which 35% of the students are girls and the rest are boys. If 80% of the boys and 90% of the girls passed in an annual examination, then the percentage of the students who failed is:

16.5

Number of girls in school  = (1400 ×  \(\frac{35}{100}\)) =  490

Number of boys = (1400 – 490) = 910

Passed boys  = (80% of 910)

= (\(\frac{80}{100}\) × 910)

= 728

Failed boys  = (910 – 728) = 182

Number of passed girls   = (90% of 490)

= (\(\frac{9}{10}\) × 490)

= 441

Failed students  = (490 – 441) = 49

Now,

Total number of failed students = (182 + 49) = 231

%age of failed students = \(\frac{231}{1400}\) × 100% = 16.5%