Answer:
1/3
Step-by-step explanation:
Since there are two points between 1 and 2, we can determine that the distance between each point is 1/3. This is because counting the number 2 (since something like 3/3 is equivalent to 1) there are 3 ticks. This means each tick represents 1/3. Therefore the distance between A and B is 1/3.
