What does "par" mean in this sentence:
The exam was easier than par.
Etymonline.com says this about par:
1620s, "equality," also "value of one currency in terms of another," from L. par "equal, that which is equal, equality" (see pair). Meaning "average or usual amount" is first attested 1767. Golf usage is first attested 1898. Figurative use of par for the course is from 1928.
Par in the game of golf means the number of strokes it should take for the scratch (handicap = 0) golfer to complete the hole.
This term has been expanded metaphorically to mean something of average difficulty. An exam that's easier than par is easier than what you would expect.
Well, this sense of "par" is typically used in the phrase "par for the course", and it means "expected" or "average". It seems to come from golf, which got it from Latin: http://en.wikipedia.org/wiki/Par_(score)#Par
The level of the exam was below average.