To convert from Fahrenheit to Celsius, you can use the following formula:
\[ C = \frac{5}{9} \times (F - 32) \]
Where \( C \) is the temperature in degrees Celsius and \( F \) is the temperature in degrees Fahrenheit.
In this case, the boiling point of petrol is 203°F. Plugging in the value:
\[ C = \frac{5}{9} \times (203 - 32) \]
Calculating inside the parentheses first:
\[ 203 - 32 = 171 \]
Now, substituting this back into the equation:
\[ C = \frac{5}{9} \times 171 \]
Now multiply:
\[ C = \frac{5 \times 171}{9} = \frac{855}{9} = 95 \]
Therefore, the boiling point of petrol in degrees Celsius is 95°C.