The ratio of number of girls and boys in a class is 3 : 1. If 50% of girls and 75% of boys are 5 feet tall or above, then what is the percentage of students in the class who are smaller than 5 feet?
The ratio of number of girls and boys in a class is 3 : 1. If 50% of girls and 75% of boys are 5 feet tall or above, then what is the percentage of students in the class who are smaller than 5 feet?
The correct option is C 43.75
Given: Girls : Boys = 3:1
Assuming there are x students in the class:
Number of girls = 0.75x.
And, number of boys = 0.25x.
Given: 50% of girls are 5 feet tall or above , so,
Number of girls in class who are 5 feet tall or above = 50% of 0.75x = 0.375x girls.
Similarily, 75% of boys are 5 feet tall or above, so,
Number of boys in class who are 5 feet tall or above = 75% of 0.25x = 0.1875x boys.
So, Number of girls in class who are smaller than 5 feet = (0.750 - 0.375)x = 0.375x girls.
And, Number of boys in class who are smaller than 5 feet = (0.2500 - 0.1875)x = 0.0625x boys.
Number of students in the class who are smaller than 5 feet = (0.375+0.0625) x = 0.4375x.
Or, percentage of students in the class who are smaller than 5 feet = 43.75%.
43.75
Given: Girls : Boys = 3:1
Assuming there are x students in the class:
Number of girls = 0.75x.
And, number of boys = 0.25x.
Given: 50% of girls are 5 feet tall or above , so,
Number of girls in class who are 5 feet tall or above = 50% of 0.75x = 0.375x girls.
Similarily, 75% of boys are 5 feet tall or above, so,
Number of boys in class who are 5 feet tall or above = 75% of 0.25x = 0.1875x boys.
So, Number of girls in class who are smaller than 5 feet = (0.750 - 0.375)x = 0.375x girls.
And, Number of boys in class who are smaller than 5 feet = (0.2500 - 0.1875)x = 0.0625x boys.
Number of students in the class who are smaller than 5 feet = (0.375+0.0625) x = 0.4375x.
Or, percentage of students in the class who are smaller than 5 feet = 43.75%.
