The total number of decision variables in the objective function of an assignment problem of size $$n\,\, \times \,\,n$$ ($$n$$ jobs and $$n$$ machines) is

It is desired to avoid interference in a pair of spur gears having a 20^o pressure angle. With increase in pinion to gear speed ratio, the minimum number of teeth on the pinion

For the given statements:
($$I.$$) $$\,\,\,$$ Mating spur gear teeth is an example of higher pair
($$II.$$) $$\,\,\,$$ A revolute joint is an example of lower pair.

Indicate the correct answer.

Which one of the following is used to convert a rotational motion into a translational motion?