Problem Solving

A certain library assesses fines for overdue books as follows. 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 double. Whichever results in the lesser amount? What is the total fine for a book on the fourth day it is overdue?

A $0.60
B $0.70
C $0.80
D $0.90
E $1.00

0.10+0.20+0.30+0.30 = 0.90

aatech wrote:0.10+0.20+0.30+0.30 = 0.90

Shouldn't it be
Day I: 0.10
Day II: 0.10 + 0.10 = 0.20
Day III: 0.20 + 0.20 = 0.40
Day IV: 0.40 + 0.30 = 0.70

Total fine: 0.70

apurohit wrote: Shouldn't it be
Day I: 0.10
Day II: 0.10 + 0.10 = 0.20
Day III: 0.20 + 0.20 = 0.40
Day IV: 0.40 + 0.30 = 0.70

Total fine: 0.70

Yup.... You are correct.. .

I think that the reasoning should be as follows:
1st day fine = 0.10
2nd day fine = (0.10 + 0.10 = 0.20) or (0.10 + 0.30 = 0.40) Go with $0.20 (since it's lesser)
3rd day fine = (0.20 + 0.20 = 0.40) or (0.20 + 0.30 = 0.50) Go with $0.40 (since it's lesser)
4th day fine = 0.40 + 0.30 = $0.70
(B) is the correct answer

Am I correct?