A total of 520 students sat for the History test. ²₃ of the boys and ⁹₁₀ of the girls passed the test. The same number of girls and boys failed the test. How many more girls than boys passed the test?
Fraction of the boys that failed the test
= 1 - ²₃
= ¹₃

Fraction of the girls that failed the test
= 1 - ⁹₁₀
= ¹₁₀

Number of boys and girls that failed the test is the same. Make the numerators the same.
¹₃ Boys = ¹₁₀ Girls

Total number of boys = 3 u
Total number of girls = 10 u

Total number of students
= 3 u + 10 u
= 13 u

13 u = 520

1 u = 520 ÷ 13 = 40

Number of boys that passed the test = 2 u
Number of girls that passed the test = 9 u

Number of more girls than boys who passed the test
= 9 u - 2 u
= 7 u
= 7 x 40
= 280

Answer(s): 280