An internet provider needs to lay a cable between towns A and B on the opposite
sides of a river at its two-mile wide estuary. Town B is 8 miles downstream from
town A. (See image.) It cost $25,000 per mile to lay cable under water and
$10,000 per mile to lay cable on land. Find the length of the underwater cable and
the length of the underground cable that will minimize the cost for the
company. Find the exact value and then round your answer to the nearest
hundredth.
