The sum of the digits of a two-digit number is $15$. The number obtained by interchanging its digits exceeds the given number by $9$. Find the original number.

The difference between a $2$-digit number and the number obtained by interchanging its digits is $63$. What is the difference between the digits of the number?

In a $3$-digit number, the tens digit is thrice the units digit and the hundreds digit is four times the units digit. Also, the sum of its digits is $16$. Find the number.

Test the divisibility of $94$ by $2$.

Test the divisibility of $570$ by $2$.

Test the divisibility of $285$ by $2$.

Test the divisibility of $2398$ by $2$.

Test the divisibility of $79532$ by $2$.

Test the divisibility of $13576$ by $2$.