1 liter of petrol in London costs £1.029
Since 1 gallon consist of 3.7854 liters, the cost of 3.7854 liters is calculated as:
Cost of 1 gallon of petrol in London = 3.7854*1.029 =£3.8951766
Next, we convert the pounds (£) to dollar($)
Since the exchange rate is 1$ =£ 0.497
£3.8951766 in $ = £3.8951766/£ 0.497 = 7.837$
The price of London petrol in dollars ($) per gallon =$7.84 (Rounded to nearest cents)