If one is added to all the even digits and two is

Solution

3          9          8          4          5          2          5          7          8          3          1          7          9          5          3          3          3          5          9          1          9          9          7          5          5          3          3          3          1          1          Sum of digits of first half from the left end = 9 + 9 + 7 + 5 + 5 = 35. Sum of digits of second half from the right end = 3 + 3 + 3 + 1 + 1 = 11. Require difference = 35 – 11 = 24.