Correct Answer - Option 3 : 200
Given
Percentage of students above 150 cm in height = 75%
Calculation
Let the number of students in a class above 150 cm is x
Percentage of boys who are above 150 cm = ( 100 - 30)%
⇒ 70%
70% of x = 105
⇒ x = (105 × 100)/70
⇒ x = 150
Total number of students who are above 150 cm is 150
Let the total number of students in a class is y
⇒ 75% of y = 150
⇒ y = (150 × 100)/75
⇒ y = 200
∴ Total number of students is 200.