Here you can easily solve the three-pronged approach. A distinction is made here in two types of rule of three, once the "normal" and then "inverted" rule of three. The difference you can see the problem and the examples.

## Simple cross multiplication

### Question:

These questions ask for the number of x units of size B, which are in the same relation to C units of A

### Example:

10 construction workers digging 22 pits in a workday. How many pits dug in the same time 5 construction workers?

10 construction workers ≅ 22 pits

5 construction workers ≅ x pits

Formula: x = (C ⋅ B) / A, ie

x = (5 ⋅ 22) / 10 = 11, ie 11 pits

## Inverse cross multiplication

### Question:

These questions ask for the number of x units of size B, the result with c units of A the same product