Marcus' atrium 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?
Diesel at $s$ pence per litre costs 3 pence per litre more than unleaded. How many pence does it cost to buy $u$ litres of unleaded petrol?
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.