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

320

The correct answer is Option (1) → 320

Step 1: Let the number of boys and girls

Let the number of boys = B
Then the number of girls = 480 − B

Step 2: Number of students who passed

• 85% of girls pass → $0.85(480 - B)$
• 70% of boys pass → $0.70 B$

Total students passed = 75% of 480 →

$0.75 \times 480 = 360$

Step 3: Form the equation

$0.85(480 - B) + 0.70 B = 360$

$408 - 0.85B + 0.70B = 360$

$408 - 0.15B = 360$

$0.15B = 408 - 360 = 48$

$B = \frac{48}{0.15} = 320$