A total of 1090 students sat for the History mock exam. ²₃ of the girls and ⁶₇ of the boys failed the mock exam. The same number of boys and girls passed the mock exam. How many more boys than girls failed the mock exam?
Fraction of the girls that passed the mock exam
= 1 - ²₃
= ¹₃

Fraction of the boys that passed the mock exam
= 1 - ⁶₇
= ¹₇

Number of girls and boys that passed the mock exam is the same. Make the numerators the same.
¹₃ Girls = ¹₇ Boys

Total number of girls = 3 u
Total number of boys = 7 u

Total number of students
= 3 u + 7 u
= 10 u

10 u = 1090

1 u = 1090 ÷ 10 = 109

Number of girls that failed the mock exam = 2 u
Number of boys that failed the mock exam = 6 u

Number of more boys than girls who failed the mock exam
= 6 u - 2 u
= 4 u
= 4 x 109
= 436

Answer(s): 436