Aabhash777
In a survey, heights of boys and girls in School M were measured. The average (arithmetic mean) height of girls was 140 centimeters. What percent of the students surveyed were girls?
1. The average height of boys surveyed was 160 centimeters.
2. As per the survey, the average height of boys and girls combined was thrice as close to the average height of girls as it was to the average height of boys.
Given: Average Height of Girls = 140
Question: What percent of the students surveyed were girls?
Statement 1:
1. The average height of boys surveyed was 160 centimeters.
Statement 1 provides us the average height of the boys. However, the statement is not sufficient as we are not given any details on the number of girls and the number of students.
As the statement is not sufficient, we can eliminate option A and D.
Statement 2:
2. As per the survey, the average height of boys and girls combined was thrice as close to the average height of girls as it was to the average height of boys.We can use the Teeter Totter approach to work with this statement.
Average height of Boys <----------------- 3x ----------------- >(Avg height of class) <----- x -----> Average height of girls
No. of Boys / No. of Girls = \(\frac{x }{ 3x}\)
Hence the number of girls is thrice the number of boys.
What percent of the students surveyed were girls?
3x / 4x * 100 = 75%
Hence the statement is sufficient.
Option B