To find the average speed of the snail, you can use the formula for speed:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
In this case, the distance the snail moved is 6 inches, and the time taken is 120 minutes.
Now, plug in the values:
\[ \text{Speed} = \frac{6 \text{ inches}}{120 \text{ minutes}} = \frac{6}{120} \text{ inches per minute} \]
Simplifying this fraction:
\[ \frac{6}{120} = \frac{1}{20} \text{ inches per minute} \]
So, the average speed of the snail is \( \frac{1}{20} \) of an inch per minute.
The correct answer is:
StartFraction 1 Over 20 EndFraction of an inch per minute.