If $$\(x \star y=x y(x-3 y)\)$$, what is the value of $$\((2 \star 1) \star(4 \star 1)\)$$ ?

I can buy bags of chips from a vending machine for dimes. If I have dollars, at most how many bags of chips can I buy?

A square is split into four triangles, and then three of the four triangles are shaded, as shown. If the areas of the shaded ...