Given
the life expectancy of a circulating coin is 30 years
the life expectancy of a circulating dollar bill is only 1/20 as long.
Procedure
c=life expectancy of a circulating coin
p= life expectancy of circulating paper money
[tex]p=\frac{1}{20}\cdot c[/tex][tex]\begin{gathered} p=\frac{1}{20}\cdot30 \\ p=\frac{30}{20} \\ p=1.5 \end{gathered}[/tex]The answer is: life expectancy of a dollar bill = 1.5 years
