Today Puzzle #649
Puzzle No. 649 – Wednesday 8 January 2020
Nadia normally drives 5 miles to work each day, in a car which does 40 miles per gallon. She makes a new year’s resolution to cycle 3 days a week for her 48-week working year. With a petrol engine emitting about 11kg of CO2 per gallon of fuel, by what percentage will she reduce her personal overall annual 6 tonne carbon footprint?
Today’s #PuzzleForToday has been set by Dr Shaun Fitzgerald, Director of The Royal Institution
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The annual mileage saved is 48 weeks x 3 days per week x 10 miles per day (return journey) = 1440 miles per year. The annual fuel saving is 1440 miles / 40 miles per gallon = 36 gallons. The carbon saving is 11 kg CO2/gallon x 36 gallons = 396kg CO2. This is 396kg/6000kg = 6.7% of the annual 6t carbon footprint.