Correct Answer - Option 2 : 110%
Given:
Height of a boy and a girl in a class is in the ratio of 2 ∶ 3 and the number of girls and boys are in the ratio of 7 ∶ 5.
Concepts used:
Total height of boys = Height of 1 boy × number of boys
Total height of boys = Height of 1 boy × number of boys
Percentage by which height of girls is more/less than the height of boys = {(Height of girls – height of boys)/Height of boys} × 100
Calculation:
Height of a boy and a girl in a class is in the ratio of 2 ∶ 3.
⇒ Height of a boy = 2x
⇒ Height of a girl = 3x
The number of girls and boys are in the ratio of 7 ∶ 5.
⇒ Number of boys = 5y
⇒ Number of girls = 7y
⇒ Total height of boys = 2x × 5y = 10xy
⇒ Total height of girls = 3x × 7y = 21xy
Percentage by which height of girls is more/less than the height of boys = {(Height of girls – height of boys)/Height of boys} × 100
⇒ Percentage by which height of girls is more/less than height of boys = {(21xy – 10xy)/10xy} × 100 = 110%
∴ The height of girls is more than the height of boys by 110%.
