How much does u litres of unleaded cost in terms of the cost per litre of 4 star petrol?
The measures of length in ancient Rome included the $pes$ , the $passus$ and the $stadium$. $5 \; pedes= 1 \; passus$, $125 \; passus= 1 \; stadium$. The atrium (courtyard) of Marcus' home was a square with each side $50 \; pedes$ long. How many times did Marcus have to walk round his atrium to complete his daily exercise of $8 \; stadia$? Write your answer in Roman numerals.
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.