Which two actions might be taken using only the core types?

Ensuring a package is installed on a system is a fundamental action that can be performed using Puppet's core resource types. Puppet provides the ‘package’ resource type, which allows you to declare packages that should be installed, ensuring the desired state of the system. By utilizing this core capability, Puppet can manage software packages across different operating systems consistently.

Managing POSIX groups, which is another option, can also be accomplished using the core types. Puppet includes the ‘group’ resource type specifically for this purpose, enabling users to define and manage user groups easily.

Creating an instance in AWS and concatenating two file fragments to form a whole may require additional modules or custom resources that are not part of the core Puppet resource types, which is why they cannot be performed solely using the core capabilities. While Puppet can facilitate these tasks with the right modules and extensions, they are not natively supported by its core types.