Answer:
Explanation:
The answer would be 15.
It is 15 because you have to start from the left then mark the first one off then go to the right and continue that until you have one number left in the middle.
Next you will draw a little line under the first left number then go all the way to the middle number you got from marking off.
Then you will do the other side from the right to the left to the middle of the number you got from marking off.
Finally, you will go to the right side and you will do the same thing on the right side of the box you just created on the right and do the same mark off.