Exoplanets (planets outside our solar system) are an active area of modern research. Suppose you read an article stating that there is a newly discovered planetary system with three planets. The article states that the outermost planet (Planet C) goes all the way around its star in less time than the innermost planet (Planet A). According to Kepler's laws of planetary motion, is this possible?

Not possible.

Explanation:

Exoplanets are an active area of modern research. The article states that the outermost planet (Planet C) goes all the way around its star in less time than the innermost planet (Planet A). Which is not possible as it will violet Kepler's third law of planetary motion. Which says that the square of orbital period of a planet is proportional to the cube of its semi-major axis of its orbit.