A flight across the U.S. takes longer east to west than it does
west to east. This is due to the plane having a headwind flying
westward (thus slowing it down) and a tailwind flying eastward
(thus pushing it along faster). Suppose you are flying from
Philadelphia, PA to San Diego, CA. The distance between the
cities is 2,400 miles and the plane’s speed is 450 mi/hr.
What is the speed of the wind?

Question

A flight across the U.S. takes longer east to west than it does
 west to east.  This is due to the plane having a headwind flying 
westward (thus slowing it down) and a tailwind flying eastward 
(thus pushing it along faster).  Suppose you are flying from
 Philadelphia, PA to San Diego, CA.  The distance between the 
cities is 2,400 miles and the plane’s speed is 450 mi/hr.  
What is the speed of the wind?