A total of 990 students sat for the Chinese mock test. ²₅ of the boys and ⁷₁₀ of the girls failed the mock test. The same number of girls and boys passed the mock test. How many more girls than boys failed the mock test?
Fraction of the boys that passed the mock test
= 1 - ²₅
= ³₅

Fraction of the girls that passed the mock test
= 1 - ⁷₁₀
= ³₁₀

Number of boys and girls that passed the mock test is the same. Make the numerators the same.
³₅ Boys = ³₁₀ Girls

Total number of boys = 5 u
Total number of girls = 10 u

Total number of students
= 5 u + 10 u
= 15 u

15 u = 990

1 u = 990 ÷ 15 = 66

Number of boys that failed the mock test = 2 u
Number of girls that failed the mock test = 7 u

Number of more girls than boys who failed the mock test
= 7 u - 2 u
= 5 u
= 5 x 66
= 330

Answer(s): 330