The Boy-Boy Paradox (VIDEO!)

Lulu has two children. You are told that at least one of her children is a boy who was born on a Tuesday. What is the probability that her other child is also a boy? The answer will surprise you! (See the addendum! There is a trap with the first approach I took, and I fell into the trap myself!!)

Boy-Boy Paradox
Addendum to Boy-Boy Paradox

Also check out my videos to BERTRAND’s PARADOX and the MONTY HALL PROBLEM.

• ON-LINE SHORT COURSES!

  QUADRATICS, Permutations and Combinations, EXPLODING DOTS, and more!

  Written for educators - and their students too! - this website, slowly growing, takes all the content Tanton has developed in his books, videos, and workshops, and organizes it into short, self-contained, and complete, curriculum units proving that mathematics, at all points of the school curriculum, can be joyous, fresh, innovative, rich, deep-thinking, and devoid of any rote doing! Let's teach generations of students to be self-reliant thinkers, willing to flail and to use their common sense to "nut their way" through challenges, to assess and judge results, and to adjust actions to find success. (Great life skills!)

  CHECK OUT: www.gdaymath.com

• Books

  • Thinking Mathematics! (TEN VOLUMES)
  • Solve This: Mathematical Activities for Students and Clubs
  • Encyclopedia of Mathematics
  • Geometry I & II

• Get in touch

  Email: tanton.math@gmail.com