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:

Total number of students in a school is 1400.

35% of the students are girls and the rest are boys.

Number of girls = $$\frac{35}{100}\times1400$$ = 490

Number of boys = 1400 - 490 = 910

80% of the boys and 90% of the girls passed in an annual examination.

Number of students passed in the examination = $$\frac{80}{100}\times910+\frac{90}{100}\times490$$ = $$728+441$$ = 1169

Number of students failed in the examination = 1400 - 1169 = 231

Percentage of the students failed in the examination = $$\frac{231}{1400}\times100$$

= 16.5%

Hence, the correct answer is Option A