If you want to check yourself:

Cost of fuel(litre) x 4.54 = cost per gallon

Divide total cost by cost per gallon = number of gallons used

Divide number of miles by number of gallons = MPG.

So £1.38x 4.54= £6.36 per gallon

£35/£6.36 = 5.58 gallons

145.2/5.58 = 26MPG