Answer:
If a penny represents one years, 4.54 billion pennies are needed to represent the age of the Earth.
Explanation:
The equivalent number of pennies is the age of the Earth divided by the age of a penny. That is:
[tex]n = \frac{4.54\times 10^{9}\,years}{1\,\frac{year}{penny} }[/tex]
[tex]n = 4.54\times 10^{9}\,pennies[/tex]
If a penny represents one years, 4.54 billion pennies are needed to represent the age of the Earth.