Correct Answer - Option 1 : 210
Given:
Percentage of girls in a class = 50%
After joining 10 girls number of girls increased by 10%
Calculation:
Let the number of students before joining the 10 girls be x.
According to the question,
Number of girls = x × 50%
⇒ 50x/100
⇒ 0.5x
After joining 10 girls, number of girls increased by 10%
Number of girls = 0.5x × 110%
⇒ 0.55x
⇒ 0.55x = 0.5x + 10
⇒ 0.05x = 10
⇒ x = 200
Now, total number of students = x + 10 =210
∴ The total number of students at present is 210.