Answer:
Size 9
Explanation:
The range is the highest value - the lowest value.
If the range is three, therefore the highest value - lowest value is 3
If 2 people in the family wear size 6, we can count that as 1 value. Since the question says that his shoe size can't be 3, so we let x be the number with the higher value.
x - 6 = 3
x = 9
Therefore Lee's shoe size is 9