In a class, 60% of the students are girls and the rest are boys. 45% of the girls pass an examination and 40% of the boys failed. If the number of girls who failed is 66, the number of boys who passed the examination is:

48

60% =  \(\frac{3}{5}\) & 45% =  \(\frac{9}{20}\) & 40% =  \(\frac{2}{5}\)

Let Total number of students = 100x

Number of girls students =  \(\frac{3}{5}\) × 100x = 60x

Number of Boys students = 100x - 60x = 40x

Number of passed Girls =  \(\frac{9}{20}\) × 60x = 27x

Number of failed girls = 60x - 27x = 33x

ATQ ,

33x = 66

x = 2

Total number of students = 100 × 2 = 200

Number of failed boys =  \(\frac{2}{5}\) × 40x = 16x

Passed boys = 24x = 24 × 2  = 48