73.6 miles according to Google Earth.
it will cost you 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 dollars to get from west palm beach to Miami
It is 7.39 miles according to MapQuest.
35 hours
70 miles taking either I-95 or the TURNPIKE (to MIAMI via I-95 SOUTH at the GOLDEN GLADES INTERCHANGE, just north of Miami) SOUTH.