In a class of the students are girls and rest are boys. If of the girls and  of the boys are absent, what part of the total number of students are present?

Given:

Fraction of girls = (3/4)

Fraction of boys = (1 - 3/4) = (1/4)

Fraction of absent girls = (2/3)

Fraction of absent boys = (1/2)

Formula used:

Part of students present = Total students × [Fraction of girls × (1 - Fraction of absent girls) + Fraction of boys × (1 - Fraction of absent boys)]

Calculation:

Let the total students = 1 

Fraction of girls present = (3/4) × (1 - 2/3)

⇒ (3/4) × (1/3) = (1/4)

Fraction of boys present = (1/4) × (1 - 1/2)

⇒ (1/4) × (1/2) = (1/8)

Total fraction of students present = Fraction of girls present + Fraction of boys present

⇒ (1/4) + (1/8)

⇒ (2/8) + (1/8) = (3/8)

∴ The correct answer is option (2).