Answer:
The rule could cost 24 cents at most.
Explanation:
Let x cents be the price of the ruler.
Alice is 22 cents short, so Alice has x - 22 cents.
Betty is 3 cents short, so Betty has x - 3 cents.
When they combine their money they have
x - 22 + x - 3 = 2x - 25 cents.
This amount is still not enough, so

Solve this inequality:

The rule could cost 24 cents at most.