For a collection of questions that encourages students to *think* about mean and median rather than just crunch numbers, there’s no resource to beat this one that is available free to download from the TES site. (You will need to create a TES login account – that’s free too).
https://www.tes.com/teaching-resource/mean-and-median-problems-and-practice-11180656
Maths Tutor Bournemouth 