To find out how much of the cake each friend ate, you need to divide the total amount of cake that was eaten by the number of friends.
Total amount of cake eaten = \( \frac{3}{4} \)
Number of friends = 9
Amount of cake eaten by each friend = \( \frac{3}{4} \div 9 \)
This can be calculated as follows:
\[ \frac{3}{4} \div 9 = \frac{3}{4} \times \frac{1}{9} = \frac{3 \times 1}{4 \times 9} = \frac{3}{36} = \frac{1}{12} \]
Therefore, each friend ate \( \frac{1}{12} \) of the cake.
The correct response is \( \frac{1}{12} \).