To find out how many turtles correspond to 18 sea lions, we can start with the ratio given: there are 5 turtles for every 6 sea lions.
We can express this ratio as:
\[ \frac{Turtles}{Sea Lions} = \frac{5}{6} \]
Where \( Turtles \) is the number of turtles and \( Sea Lions \) is the number of sea lions.
Given that there are 18 sea lions, we can set up the equation:
\[ \frac{Turtles}{18} = \frac{5}{6} \]
Now we can solve for \( Turtles \):
\[ Turtles = 18 \times \frac{5}{6} \]
Calculating this gives:
\[ Turtles = 18 \times \frac{5}{6} = 18 \div 6 \times 5 = 3 \times 5 = 15 \]
Thus, there are 15 turtles if there are 18 sea lions.