7.1. Does there exist a four-digit natural number with distinct non-zero digits that has the following property: if this number is added to the same number written in reverse order, the result is divisible by $101 ?$
Answer. It exists.

Solution. For example, the number 1234 works. Indeed, $1234+4321=5555=101 \cdot 55$.

Remark. A number $\overline{a b c d}$ with distinct non-zero digits satisfies the condition if and only if $a+d=b+c$.

Comment. Any correct example with verification that it fits - 7 points.

Any correct example without verification that it fits - 5 points.