Explain how LPG and CNG work as household and commercial vehicle fuels?

Explanation

### Step-by-Step Solution:

1. **Definition of LPG and CNG**:
- LPG stands for Liquefied Petroleum Gas, while CNG stands for Compressed Natural Gas. Both are used as fuels in households and vehicles.

2. **Source of LPG**:
- LPG is obtained by refining crude oil. The refining process separates various components of oil, and LPG is one of the byproducts.

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