As I am reading this question, I feel that perhaps a part of the question is missing. I will assume that all the information are there and will answer it accordingly.
I think the tricky part about this question is that it’s an integer game – meaning that the number selected could be a negative (-10) or positive (10). So you need to work through all the negative number and positive number with each of the operation (+, - , x, and /) to see which operation with which type of integer would produce the highest score.
For example: 10 + 5 = 15 but (-10) + (-5) = -5
After doing all the math, the highest score for Jan is:
10 x 5 = 50
The highest score for Tom is:
1 + 3 = 4
(As multiplying 1 * 3 = 3 so adding the positive integers would give you a higher score).