What is common between the following pairs of substances
LPG and petrol

Explanation

**Step-by-Step Solution:**

1. **Identify the Substances**: The question asks about the commonality between LPG (Liquefied Petroleum Gas) and petrol.

2. **Define LPG**: LPG is a flammable mixture of hydrocarbon gases, primarily propane and butane. It is used as a fuel gas in heating appliances and cooking equipment.

3. **Define Petrol**: Petrol, also known as gasoline, is a derivative product of crude oil. It is primarily used as fuel for vehicles.

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