A <Cartesian product> with the <empty set> is empty: there is no possible second coordinate. Thus the requested <cardinality> is \b[$0$], independently of the first factor's <power set>.

Solution

Past exam of the year 1 of the computer science course of the University of Oxford / 2017 / Discrete mathematics, continuous mathematics and probability / 1 / c / ii / Solution

 Solution (source code)