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

A circular object of radius r rolls without $$V$$ slipping on a horizontal level floor with the center having velocity $$V.$$ The velocity at the point of contact between the object and the floor is

A rigid link PQ is 2 m long and oriented at 20^o to the horizontal as shown in the figure. The magnitude and direction of velocity V_Q, and the direction of velocity V_P are given. The magnitude of V_P(in m/s) at this instant is

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.