Question

In an examination, out of 480 students 85% of the girls and 70% of the boys passed. How many boys appeared in the examination if total pass percentage was 75%?

• A. 370
• B. 340
• C. 320
• D. 360

Answer 1

The Correct Option is C

In the given problem, we need to determine how many boys appeared in an examination. Let's denote the number of girls as \( G \) and the number of boys as \( B \). The total number of students is \( G + B = 480 \).

We know 85% of the girls passed, and 70% of the boys passed. The overall pass percentage is 75%, meaning:

\(\frac{0.85G + 0.70B}{480} = 0.75\)

Multiply both sides by 480 to eliminate the fraction:

0.85G + 0.70B = 360

We also have the equation for the total number of students:

G + B = 480

Substituting \( G = 480 - B \) into the first equation:

0.85(480 - B) + 0.70B = 360

Expanding, we have:

408 - 0.85B + 0.70B = 360

Combining like terms gives:

408 - 0.15B = 360

Simplify by subtracting 408 from both sides:

- 0.15B = -48

Divide by -0.15 to solve for \( B \):

B = 320

Thus, the number of boys who appeared in the examination is 320.