Question 166173
Well I guess we have to count how many of each are in a kilometer.
From a GOOGLE search, I found the following information,
dime:1.35 mm thickness
quarter:1.75 mm thickness
Let's assume it's correct.
So 1 km, which equals (1000)(1000)mm, there are this many dimes,
{{{N[d]=(1000)(1000)/(1.35)=740741}}}
Each dime is $0.10, so the total in 1 km is,
{{{T[d]=0.10(740741)=74074.10}}}
Similarly for the quarters,
{{{N[q]=(1000)(1000)/(1.75)=571429}}}
Fewer of them, but what about the total value,
{{{T[q]=0.25(571429)=142857}}}
Wow, it's almost double.
The exact difference is 
{{{T=T[q]-T[d]=142857-74074=68783}}}
$68,783 difference between the two coin kilometers.
That's a lot of coin wrappers!