Arm Wrestling

(Students getting ready to take a test)
Student: "Mrs. A, how many questions are there going to be on the test?"
Me: "Only 40."
Student (clearly disgusted): "That's it?!  I was expecting 75!"
Me: "I can give you a test with 75 questions if you would like."
Student: "No, I'm good."
Me: "Ok, how about this...we arm wrestle.  If you win, you take the test with 40 questions and if I win, you take the test with 75 questions."
(All students in the class cheer for the arm wrestling to take place)
(Student pauses)
Student: "Ok."
(We arm wrestle and I use two hands and beat the student)
Student: "No fair!  You used two hands and now I have to take the longer test!"
Me: "Well, you learned two lessons today.  One: always go over the rules before arm wrestling.  Two: Don't complain about the length of a test."
(I gave the student the 75 question test)
(I only required that the student answer 40 questions)