Question

Ernie walks 1/6 mile in 1/12 hour when he walks along the river trail. How many miles does Ernie walk when he hikes on the trail

Answer 1

"How many miles does Ernie walk when he hikes on the trail"

You just stated he walked 1/6 mile

Did you mean, how many miles does Ernie walk per hour when he hikes on the trail?

rate = distance / time
= (1/6) / (1/12)
= 2