Which of the following cannot be the sum of a 6-digit number and the number formed by reversing its digits?

A.777777

B.1234442

C.424523

D.951467

D.951467

Let the numbers be abcdef and fedcba. When we add them we get

100000(a+f) + 10000(b+e) + 1000(c+d) + 100(d+c) +10(b+e) + (f+a)
= 100001(a+f) + 10010(b+e) + 1100(c+d)

Whatever (a+f) is, that will be the first digit and the last digit. (a+f) can be anything from 2 (=1+1) to 18 (=9+9)

Moreover,Add the numbers, club them, and you’ll see that the sum is divisible by 11.

Only option D satisfies this