- A balloon is a kind of container
- A balloon filled with helium
- So, a balloon filled with helium is an example of a container filled with helium

- Helium is a kind of element
- Elements are pure substances
- Hence, helium is a pure substance

- A balloon filled with helium is an example of a container filled with helium
- Helium is a pure substance
- Hence, a balloon filled with helium is an example of a container filled with a pure substance

Therefore, a balloon filled with helium is an example of a container filled with a pure substance
Which of the following is an example of a container that is filled with a pure substance rather than with a mixture?
- A balloon is a kind of container 
- Helium is a kind of element 
- Elements are pure substances 
- A balloon filled with helium