Erica and John are standing in the same cattle field at the same time. Erica can see the same number of bulls and cows in the field. However, John can see twice as many cows as bulls. How can this be and how many cows and bulls are there in the field?
As ever, please do NOT post your answer but feel free to say if you have solved it and how long it took. Solution on Monday!
Oh, and here is a photo of my good self helping to launch the Edinburgh International Science Festival yesterday, with Festival Director Simon Gage.