Answer:
The answer is $0.70.
Step-by-step explanation:
On the first day that a book is overdue, the total fine is $0.10.
For each additional day that the book is overdue, the total fine is either increased by $0.30 or doubled, whichever results in the lesser amount.
So, fine on 1st day overdue = $0.10
Fine on 2nd day overdue = [tex]0.10\times2=0.20[/tex] (this is lesser than the value if $0.30 is added)
Fine on 3rd day overdue = [tex]0.20\times2=0.40[/tex] (this is lesser than the value if $0.30 is added)
So, fine on 4th day overdue will be = [tex]0.40+0.30=0.70[/tex] dollars. (here doubling will give higher value)
So, the answer is $0.70.