In Japan, license plates consist of two numbers followed by another two numbers.
Maki Kaji is a Japanese businessman who takes pictures of all license plates for which the
first pair multiplied by each other equals the second pair.
For example, 11 01 can be thought of as 1 x 1 = 1.
Assuming that no Japanese car has 00 for the second pair of digits, how many possible
combinations are there?
Solution to the Problem:
The answer is eighty-one.
Each plate that Kaji photographs is a line in the times tables of the digits 1 to 9.
11 01 is 1 x 1 = 1.
12 02 is 1 x 2 = 2.
Here is the full set of license plates:
Kaji has already collected more than 50 pictures of license plates.
Once he has gathered the full set of times tables, he plans to exhibit them in a gallery.
Correctly solved by:
| 1. Steven Muller | Clearbrook, Virginia |
| 2. Dylan Martin |
Mountain View High School, Mountain View, Wyoming |
| 3. Jacob Harmon |
Mountain View High School, Mountain View, Wyoming |