A plastic crate in the form of an open cuboid is made from a piece of plastic measuring 40 cm by 60

cm with squares of side x cm cut out of the corners.

AFind an expression for the volume V of the crate in terms of x.

BFind the x-intercepts and discuss what they represent.

CFind the local maximum and minimum values of V.

DExplain why, in real life, V cannot be equal to one of the values you found in part c.