Formulas
- Direct: X = B x C / A
- Inverse: X = A x B / C
Example
If 4 books cost 10, how much do 6 cost? It is direct: 10 x 6 / 4 = 15.
Frequently asked questions
When is it direct?
When one value goes up, the other goes up too.
When is it inverse?
When one goes up, the other goes down, like workers and days.
Does it work with decimals?
Yes.
Is it free?
Yes.