in early 2015 the price of oil dropped and petrol became cheaper.
in United States, the cost of petrol was $2.o9 per US gallon.
in UK the cost of petrol was £1.09 per litre.
the exchange rate was £1=$1.51
1 US gallon= 3.8 litres
approximately how many times more expensive is petrol in the UK than the USA?