Problem Solving

A library assesses fines for overdue books as follows. On the first day that the 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, which results in the lesser amount. What is the total fine for a book on the fourth day it is overdue?

the total fine is increase by .30 per day so
day 1 .10
day 2 .40
day 3 .70
day 4 1.00

so $1.00 is the total fine on day four

or
the fine is double each day
day 1 .10
day 2 .20
day 3 .40
day 4 .80
So .80 is the less than $1.00. Why is the answer $.70 instead of $.80 ?




Answer:
$0.70

the q is asking which ever is less
therefore
day1 fine =0.1
day2=0.1*2 or 0.4(whichever is less)=0.2.
day3=0.4 or 0.7=0.4(lower value)
day 4=0.8 or 0.4+0.3=0.7 ; hence 0.7(lower value)

Thanks so much for clarifying what they were asking! I completely misinterpreted the question.

Hello! My approach:

option 1: 0,1 + 0,3*3 = $1 (1st day + 0,3 for each additional day)

option 2: 0,1 + 0,2*3 = 0,7 (1st day + double 0,1 for each additional day)

Hence, 0,7 is the answer.

Hope, this might help someone

day 1= 0.1
day 2= 0.2 and not 0.3 as 0.3+0.11>0.2+0.1
day 3= 0.3 again 0.3+0.2+0.1< 2(0.3)+0.2+0.1
day 4= 0.3

total= 0.9