Fundamentals - Real Numbers - Chapter 1.1, Problem 10E

a. There are no positive integers. b. -500 is a negative integer, so it is not a natural number, but it is still an integer. -$\frac{20}{5}$ simplifies out to -4 which is a negative integer. $\sqrt{1}6$ simplifies out to -4 or 4. It is not a natural number because -4 is negative. c. 1$\frac{2}{3}$, 1.3, 1.333333..., 5.34, and $\frac{246}{579}$ are rational numbers because they can be represented in ratios of two numbers. d. $\sqrt{5}$ is irrational because it cannot be represented in a ratio of two numbers.