Cutting The Paper

Suppose that I cut a rectangular piece of paper in straight lines of equal length, parallel to one of the edges. If it took me $s$ seconds to cut a paper into $k$ pieces, how long will it take me to cut another paper into $4k$ pieces at the same rate?

Details and Assumptions:

• A cut is defined to be the line from one edge to another.

• Papers are clean and fresh as new!

• $k \geq 2$ is a positive integer, and $s$ is a positive real number.