Let \( L \) represent the number of seashells Lucy has. According to the problem, Daisy has 6 more than three times the number of seashells Lucy has:
\[ D = 3L + 6 \]
We know that Daisy has 36 seashells:
\[ 36 = 3L + 6 \]
Now, we can solve for \( L \):
- Subtract 6 from both sides:
\[ 36 - 6 = 3L \] \[ 30 = 3L \]
- Divide both sides by 3:
\[ L = \frac{30}{3} = 10 \]
So, Lucy has 10 seashells.
The correct response is 10.