The problem :
A spy climbs out of a submarine into a rubber boat $2$ miles east of point $P$ on a straight north-south shoreline. He wants to get to a house on the shore $6$ miles north of $P$. He can row $3mi/h$ and walk $5 mi/h.$ He intends to row directly to a point north of $P$ and then walk the rest of the way.
a)How far north of $P$ should he land in order to get to the house in the shortest possible time?
b)How long does trip takes?
c)How much longer will it takes if he rows directly to $P$ and then walks to the house?
d**)If the rubber boat has a small outboard motor and can go $5 mi/h$, then it is obvious by comman sense that the fastest route is entirely by boat.What is the slowest speed which the fastest route is still entirely by boat?
