Chalk

Five eviction policies and one fixed run of ten questions at the counter. Step through it yourself.

The slate is full and someone asks for something new. A chai stall keeps its prices on a small slate next to the stove, and ten customers ask for things in a fixed order. try this Pick Longest unasked, press Add next question until all ten are asked, then drag Lines the slate holds and watch The register. Longest unasked tracks when each line was last read and erases the one read longest ago. A rare line having one busy morning can look permanently popular.