To answer this question we can see in the graph that the first quartile Q1 is in the value 2. That means that 25% of the days were sold 2 books or less. If there were 60 days in total, this means that less than two books were sold for 15 days.
The third quartile Q3 has a value of 12. This means that 75% of the days (45 days) were sold 12 books or less.
Then for 45 days less than 12 books were sold and you know that in 15 of those 45 days less than 2 books were sold.
Finally, the days that sold between 2 and 12 books were
RIC = 54-15 = 30 days
The correct answer is the third option: 30 days
