On the eve of Spain’s annual Christmas Lottery, math and gambling enthusiasts are being invited to test their knowledge and logic skills. This time, the challenge centers around probabilities that anyone who’s ever bought a lottery ticket might encounter. The focus is on a box filled with dozens of tickets—and the question is: what are the odds of drawing two odd-numbered tickets in a row?
The problem’s author, a mathematics teacher, notes that there are currently between 30 and 40 tickets in the box, but the exact number is unknown. All we know is that if you randomly draw two tickets, the chances that both have even numbers is exactly one third. Now, participants are asked to calculate the probability that both drawn tickets have odd numbers.
Problem statement
The instructions emphasize that tickets are drawn one at a time, with the first not returned to the box. This means that after the first draw, the total number of tickets decreases by one—along with the count of odd or even tickets, depending on which type was chosen first.
To solve the problem, it’s important not only to name the correct answer but also to explain your reasoning. The organizers expect participants to provide a clear and logical explanation of how they arrived at their conclusion, rather than just formal mathematical calculations. This approach makes the puzzle accessible to a wider audience, including schoolchildren and students.
A challenge for everyone
The challenge is designed for people with different levels of experience. Even if you don’t consider yourself an expert in probability theory, it’s worth giving it a try. What’s important is not just calculating the probability, but also explaining why your answer is the way it is. This approach helps develop analytical thinking and teaches you to express your ideas clearly to others.
Organizers emphasize that answers will be accepted up to and including December 18, 2025. The solution will be published the following day so everyone can compare their reasoning with the official answer.
Spanish tradition
The Christmas lottery is one of the most anticipated events in Spain. Millions of people across the country buy tickets, hoping for good luck. For many, participating in the lottery has become not just a chance to get rich, but a part of national tradition. This year, organizers decided to add an intellectual element to make waiting for the drawing even more exciting.
The lottery ticket challenge is a great way to take your mind off everyday worries and test your math skills. It’s also an opportunity to connect with like-minded people, discuss different approaches, and maybe discover something new about the world of probability.
How to participate
To participate, simply send your answer with an explanation to the specified email address by the end of December 18. You don’t need to use complex formulas or specialized terminology—what matters most is that your reasoning is clear and logical. The organizers particularly encourage young people to take part, but everyone interested is welcome to try.
No prizes or winners are guaranteed, but the chance to test yourself and compare your logic with others is already a great incentive. Moreover, challenges like this help you look at familiar things from a new perspective and develop analytical skills useful not only for lotteries, but for life in general.
