Answer:
$8 charge for each additional person
Step-by-step explanation
$40/night for each person
First 4 people already paid.
Leftover are 5 people.
9-4=5
Since first 4 people paid, the rest to be paid is $40.
$80-$40=$40
To find the charge for each person, divide the amount of money left by the amount of people left.
40รท5= 8
$8 is the additional charge for each additional person.