What is the ratio of the number of books for subject B1 to the average number of books per subject?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 10 : 11.
The number of books for subject B1 = 120
We know that,
Average = Sum of observations/Number of observations
Average number of books per subject = (120 + 150 + 150 + 120 + 120)/5 = 660/5 = 132
Required ratio = 120 : 132 = 20 : 22 = 10 : 11