Question

The age of the Earth is 4.54 billion years old. The circumference of the Earth is 40,074km. The diameter of a penny is 1.9cm. One penny represents one year of time. How many pennies would you need to represent the age of the Earth. Express your answer as a full number with units in "pennies", no spaces

Answer 1

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:

$n = \frac{4.54\times 10^{9}\,years}{1\,\frac{year}{penny} }$

$n = 4.54\times 10^{9}\,pennies$

If a penny represents one years, 4.54 billion pennies are needed to represent the age of the Earth.