Question

let sets a and b be defined as follows.
a = { -27, -26, -25, -24, -23, -22, -21 }
b is the set of even numbers greater than or equal to 6 and less than or equal to 10
(a) find the cardinalities of a and b.
n(a) =
n(b) =

Explanation:

Step1: Count elements in set A

Count the values in $A=\{-27, -26, -25, -24, -23, -22, -21\}$: there are 7 elements, so $n(A)=7$.

Step2: Define set B first

List even numbers where $6\leq x\leq10$: $B=\{6,8,10\}$

Step3: Count elements in set B

Count values in $B$: there are 3 elements, so $n(B)=3$.

Answer:

$n(A)=7$, $n(B)=3$