Question: how many litres in one tonne?
Answer: Litres are a measure of volume (like pints), whereas tonnes are a measure of mass, also often wrongly referred to as weight. So it depends on the density of the substance. If it is water it is easy - 1 litre = 1 kg, so 1000 litres = 1000kg = 1 tonne. A tonne is 1000kg.