If all the even digits are changed to the next digit whereas all odd digits are changed to the previous digit in the number series, then all the digits are rearranged in ascending order from left to right. Which of the following numbers the positions of two or more digits remain unchanged?
I. 3574826
II. 4857923
III. 5986432
A. Both I and III
B. Only II
C. Both I and II
D. Only I
E. None of these
Sol:
From I: 3574826 → 2465937 → 2345679 (no digit remains unchanged)
From II: 4857923 → 5946832 → 2345689 (no digit remains unchanged)
From III: 5986432 → 4897523 → 2345789 (no digit remains unchanged)
Hence, option E is the correct choice.
