Brain Teasers
Boxes of Notes
One day in the middle of the term, Leong was told to collect some lecture notes from the photocopy lady for his and the other four classes. The lecture notes were neatly stacked in boxes, with the number of lecture notes written on the box and the class written on a label pasted outside. On the way back to the classroom, a strong gust of wind blew the labels off the boxes.
If all five classes have different number of students, and there are no extra lecture notes in each box, what is the probability of Leong relabelling at least one of the boxes correctly?
If all five classes have different number of students, and there are no extra lecture notes in each box, what is the probability of Leong relabelling at least one of the boxes correctly?
Answer
100%. Leong's class is receiving one of the boxes of lecture notes, and as Leong would definitely know how many pupils are registered in his class, he can relabel the box belonging to his class correctly. No matter how, he will at least relabel one box correctly.Hide Answer Show Answer
What Next?
View a Similar Brain Teaser...
If you become a registered user you can vote on this brain teaser, keep track of which ones you have seen, and even make your own.
Solve a Puzzle
Comments hidden to avoid spoilers.
Follow Braingle!