Students' strength in a co-educational school is 3,000. If the ratio of the number of boys to the number of girls in the school is 4 : 1, then what is the mean proportion of the number of boys and girls in the school, given that only boys and girls are students in the school?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 1200.
Concept used:
Mean proportion of a and b = √ab
Calculations:
Students' strength in a co-educational school is 3,000.
The number of boys in the school = (4/5) × 3000 = 2400
The number of girls in the school = (1/5) × 3000 = 600
Hence, the mean proportion of the number of boys and girls in the school = √(2400 × 600)
⇒ √1440000 = 1200