If 2 is added to each odd digit and 1 is subtracted from each even digit in the number 62478324, then what will be the difference between the highest and the lowest digits in the number thus formed?

Given number: 62478324
Add 2 to each odd digit
Subtract 1 from each even digit
Write down the digits:
6, 2, 4, 7, 8, 3, 2, 4
Apply the rule to each digit:
6 → even → 6 - 1 = 5
2 → even → 2 - 1 = 1
4 → even → 4 - 1 = 3
7 → odd → 7 + 2 = 9
8 → even → 8 - 1 = 7
3 → odd → 3 + 2 = 5
2 → even → 2 - 1 = 1
4 → even → 4 - 1 = 3
New number after changes:
5, 1, 3, 9, 7, 5, 1, 3
Find the highest and lowest digits:
Highest = 9
Lowest = 1
Find the difference:b9 - 1 = 8