To calculate the interquartile range (IQR), you first need to find the first quartile (Q1) and third quartile (Q3) of the data. The IQR is the difference between Q3 and Q1:
\[ \text{IQR} = Q3 - Q1 \]
However, you have not provided the actual data set of minutes spent by the students. If you provide the data, I can help you calculate the interquartile range. Otherwise, based on the options provided, I can't determine the IQR without additional information.