There is a row of 15 trees in a garden. Starting from the first tree, a gardener marked every second tree, then, on his way back, he marked the first tree, and then every third tree. How many trees are left without a mark?

An architect is designing a water fountain for a park she uses the given function to model the water jet flowing from the fountain nozzles where h(x) gives the height of the water jugs in feet x feet from the starting point h(x)=-1/20x+x+15

Does anyone know how to do geometryme with this problem

Which statement accurately explains whether a reflection over the y axis and a 270° counterclockwise rotation would map figure acb onto itself?