#### Answer

a.) $A \cup C = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]$
b.) $A\cap C = [7]$

#### Work Step by Step

$Find$ $the$ $indicated$ $set$ $if:$
$A = [1, 2, 3, 4, 5, 6, 7]$
$B = [2, 4, 6, 8]$
$C = [7, 8, 9, 10]$
a.) $A \cup C$
We find the union of the variables for A and C. Place the units in chronological order
$A \cup C = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]$
b.) $A \cap C$
We find what units in A and C intercept each other. We determine that A and C only intercept at 7
$A\cap C = [7]$