Answer:
Option 3rd is correct

Explanation:
Let x be the time in minutes and f(x) be the cell phone monthly bill.
Given the statement:
if there is a monthly charge of 20 dollars plus 6 cents for each minute of use
Use conversion:
1 cent = 0.01 dollars
6 cents = 0.06 dollars
"
means 0.06 x
then;
the function represents a cell phone monthly bill is given as:
