math
posted by Anonymous .
Tne union of the set of rational numbers and the set of irrational numbers is
1 {whole number}
2 {real numbers}
3 {counting numbers}
4 {}

The UNION of sets consists of all elements in either set: it is a larger set than either set alone. That is enough to eliminate one of the possible answers.
pi (3.1415926535...) is an irrational number, so it is in the union set of rational and irrational numbers. Is pi a whole number? Is it a real number? Is it a counting number? If you know the meanings of those terms, the answer will be clear. 
is it areal number