Help Alex find his way.
Alex the geologist is in the desert, 10 miles from a long, straight road. On the road, Alex’s jeep can go 50 miles per hour, but in the desert sands, it can only go 30 miles per hour. Alex is very thirsty and wants to buy some lemonade at a gas station which is 20 miles down the road from the point on the road, N, nearest to Alex. If Alex takes the fastest route possible, it will take only 40 minutes to get to the gas station and sip some cool lemonade. What route should Alex take?