Match the type of gears with their most approximate description.

	Type of gear
		Description
P
	Helical
	1
	Axes non parallel and non intersection
Q
	Spiral Bevel
	2
	Axes parallel and teeth are inclined to the axis
R
	Hypoid
	3
	Axes parallel and teeth are parallel to the axis
S
	Rack and pinion
	4
	Axes are perpendicular and intersecting, and teeth are inclined to the axis.
		5
	Axes are perpendicular and used for large speed reduction
		6
	Axes parallel and one of the gears has infinite radius.