The IQR is the range of the box in the box and whisker plot
So if you remember how to do the average of something you are already there
You need 2 numbers
First being the lower quartile and upper quartile
48 is where the lower quartile starts and 70 is where the upper quartile finishes *NEVER USE MEDIAN IN IQR
all you have to do is subtract
70-40 and you get as an answer 22.0 being A as your answer