#### Answer

a. There are none.
b. -500, -$\frac{20}{5}$, $\sqrt 16$
c.1$\frac{2}{3}$, 1.3, 1.333333..., 5.34, $\frac{246}{579}$
d. $\sqrt 5$

#### Work Step by Step

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. $\sqrt 16$ 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.