In a cylinder, radius is doubled and height is halved, then curved surface area will be

Let the radius of a cylinder be r unit and height be h unit. Now according to question,

Radius is doubled that is 2r and height is halved that is

Now curved surface area of a cylinder is

And according to the above condition, curved surface area

This is same as the curved surface area of the cylinder with radius r and height h.

Thus option c is correct.