## Thinking Mathematically (6th Edition)

Given C={x|x <4 and x $\geq$ 12} From the given question. The given set represents the natural numbers which are less than 4 but greater than equal to 12. There is no element satisfying the given condition The given set is an empty set. The cardinal number for each set is formed by calculating the number of elements in each set. Therefore the cardinal number for given set C is n(C) = 0.