Question

If berries are ripe along the trail, hiking is safe if and only if grizzly bears have not been seen in the area.

Answer 1

Let p, q and r be the propositions

$p$ : Grizzly bears have been seen in the area.

$q$ : Hiking is safe on the trail.

$r$ : Berries are ripe along the trail.

$\implies$  If berries are ripe along the trail, hiking is safe if and only if grizzly bears have not been seen in the area.

Solution:

$\boxed{r\to(q\leftrightarrow \lnot p)}$