Answer:
10 or 22 or 15 or 40
Step-by-step explanation:
In the second for loop[for (int k = 1; k < arr[0].length; k++)], k starts from 1 instead of zero. That means that it doesn't read the first value of every row when finding num.
So if num was any of the above values, the program wouldn't work. I had the same question, and the answer for mine was 15.