Solve the Problem $12 \mathrm{mi}$ And Then Hiked an Additional $8 \mathrm{mi}$

Solve the problem. Round your answer to the nearest tenth, if necessary.
-A man rode a bicycle for $12 \mathrm{mi}$ and then hiked an additional $8 \mathrm{mi}$ . The total time for the trip was 5 $\mathrm{hr}$ . If his rate when he was riding a bicycle was $10 \mathrm{mph}$ faster than his rate walking, what was each rate?

A) Bike: $13 \mathrm{mph}$ ; hike: $3 \mathrm{mph}$
B) Bike: $14.5 \mathrm{mph}$ ; hike: $4.5 \mathrm{mph}$
C) Bike: $12 \mathrm{mph}$ ; hike: $2 \mathrm{mph}$
D) Bike: $11.5 \mathrm{mph}$ ; hike: $1.5 \mathrm{mph}$