Question

Select the correct description for each number set.(4 points)
a) (25−−√, 9, −−−√64−−√
25
,

9
,

64
)

b) ( -2.4, 0, 3.1, 81−−√
81
)

c) (−23, 79, π2
−
2
3
,

7
9
,

𝜋
2
)

d) (12−−√, 11−−√, π
12
,

11
,

𝜋
)

Answer 1

Answers (most specific usual classification containing every element):

a) Natural numbers — √25 = 5, 9, √64 = 8 (all are natural numbers).

b) Rational numbers — −2.4, 0, 3.1 are terminating decimals (rational) and √81 = 9 (rational).

c) Real numbers (mixed) — contains integers (−23, 79), a rational (7/9) and irrationals involving π, so not all rational or integer; it is a set of real numbers.

d) Real numbers (mixed) — √12, √11, π/12 and π are irrational while 11 is rational, so the set is a mixture of rationals and irrationals (real numbers).