### Instruction: During her birthday, her parents have decided to give Laura and her 2 younger brothers new cellphones. However, they are confused between the innumerable service providers. Assuming no child wants a provider that another sibling has, and that there are 20 service providers,  in how many ways can the parents grant the children their phones?### Response: So there are 20 providers and 3 children.
The first child can get any of the 20 providers.
The second child can get any of the 19 providers that the first child didn't get.
The third child can get any of the 18 providers that the first two children didn't get.