“80% of the final exam will be based on the one lecture you missed and the one book you didn’t read”

“80% of the final exam will be based on the one lecture you missed and the one book you didn’t read” is a jocular one-line saying that has been printed on GIFs. The saying was published in the book Murphy’s Law, Book Two: More reasons why things go wrong (1980) by Arthur Bloch.
 
   
OCLC WorldCat record
Murphy’s law, book two : more reasons why things go wrong
Author: Arthur Bloch
Publisher: Los Angeles : Price/Stern/Sloan Publishers, ©1980.
Edition/Format:   Print book : English
 
Los Angeles (CA) Times
HIGH LIFE : Murphy’s Law: If Anything Can Go Wrong, It Will
April 09, 1988
(...)
As applied to Academiology:
 
LAWS OF APPLIED TERROR:
 
* When reviewing your notes before an exam, the most important ones will be illegible.
* The more studying you did for the exam, the less sure you are as to which answer they want.
* 80% of the final exam will be based on the one lecture you missed about the one book you didn’t read.
     
Google Books
Reading and Study Skills
By Patricia Grant
Englewood Cliffs, NJ: Prentice Hall
1989
Pg. 72:
For example, read the following sentence from Murphy’s Law: Book Two: “80 percent of the final exam will be based on the one lecture you missed about the one book you didn’t read.”
   
Google Books
The Complete Murphy’s Law:
A Definitive Collection
By Arthur Bloch
Los Angeles, CA: Price Stern Sloan
1991
Pg. 136:
Eighty percent of the final exam will be based on the one lecture you missed about the one book you didn’t read.
 
Twitter
Hem
‏@stephen001
80% of the final exam will be based on the one lecture you missed and the one book you didn’t read.
12:34 AM - 31 Jan 2009
 
Twitter
Debs DeAngelis
‏@MDPRINT411
80% of the final exam will be based on the one lecture you missed and the one book you didn’t read.
9:55 PM - 23 Mar 2009
 
Google Books
Campus Traditions:
Folklore from the Old-Time College to the Modern Mega-University
By Simon J. Bronner
Jackson, MS: University Press of Mississippi
2012
Pg. 66:
Eighty percent of the final exam will be based on the one lecture you missed about the one book you didn’t read.
 
Twitter
Jay Perez Pablo
‏@jayAr02
80% of the final exam will be based on the one lecture you missed and the one book you didn’t read.
#AccountancyProblem
️️️️️7:11 AM - 26 Jan 2017