Question 1
If the digits of a two-digit number are reversed to form a new number, the difference between the two numbers is 45. How many different such pairs are there?
Use the source convention: a reversed form may start with zero (for example, 04 means 4). Count each pair once, regardless of order.
Enter one whole number, without units.
Use the source convention: a reversed form may start with zero (for example, 04 means 4). Count each pair once, regardless of order.
Enter one whole number, without units.