What is the answer to this math quizz?

Solving puzzles helps improve our cognitive processes, strengthens the connections between brain cells, and improves memory. And they’re also a lot of fun! So, by solving riddles, you’re basically killing 2 birds with one stone.

We like to solve some interesting and difficult puzzles. This time we found 10 riddles for you, where you need to use your logic and attention to detail. Take your time and enjoy!

The correct answer is