To solve this question, wee need to know the definition of all of these terms. A natural number is a number that is greater than or equal to 1, and integer is a number greater than or less that or equal to 0 that doesn't have a decimal part, a real number is any number that is not imaginary, and a rational number is a number that can be written as a/b with b not equal to 0. Now we can give examples.
a) -1
b) 1.1
c) π
