How long will it take you to ski a distance of 36 miles at a speed of 3 miles per 30 minutes

It will take you 6 hours to ski 36 miles

30 minutes=30 minutes(1 hour / 60 minutes)=1/2 hour.

1)we calculate the speed.
speed=distance /time

Data:
distance=3 miles
time=1/2 hour

speed=3 miles / (1/2 hour)=6 miles/hour.

2)we calculate how long will it takeme to ski a distance of 36 miles.

speed=distance / time  ⇒time=distance/ speed.

Data:
distance:36 miles
speed=6 miles/ hour.

time=36 miles / (6 miles/ hour)=6 hours

6 hours.