A car owner buys petrol at ₹ 40, ₹ 50 and ₹60 per litre for 3 consecutive years. If he spends ₹ 30,000 each year, what is the average cost of a litre of petrol? (correct to two decimal places)

Total petrol bought in first year = $$\dfrac{30000}{40} = 750$$ litres
Total petrol bought in second year = $$\dfrac{30000}{50} = 600$$ litres
Total petrol bought in third year = $$\dfrac{30000}{60} = 500$$ litres
Total petrol bought in three years = 750+600+500 = 1850 litres
Total money spent on petrol in three years = Rs.30000*3 = Rs.90000
Therefore, Average Cost of petrol per litre = $$\dfrac{90000}{1850} = Rs.48.65$$