A friend of mine tried to challenge me yesterday with this one but I can say that it can be barely called a challenge. It took me less than a minute to figure it out and make him very disappointed. Don’t worry, you don’t have to be a mathematician to solve this. If you find the answer post it and I will let you know if it was the correct one. Also, if you have a difficult problem, cipher or puzzle you are very welcome to contact me and if I like it I will post it in my challenges. You don’t even need to have the solution and even if you have it don’t give it to me. I like to be challenged so challenge me.

Based on the following calculations

9 + 3 = 3612

11 – 3 = 248

7 + 2 = 189

15 – 2 = 2613

Find the correct answer to the following calculation

13 – 3 = ?

Well done Anonymous. Your answer is correct.

Good job Alejandro Castillo. Try the other challenges.

Edited: Wrong but very close