Question

The thickness of a U.S. penny is 5.98 X 10-2 inch.

Answer 1

Answer: $1.495*10^8\ inches$

Step-by-step explanation:

For this exercise you have to remember the Product of powers property, which states that:

$(a^m)(a^n)=a^{(m+n)}$

Let be "x" the height in inches of a stack of $2.5*10^9$ pennies.

You know that the thickness of 1 pennie is $5.98*10^{-2}\ inches$, then, you can write the following proportion:

$\frac{5.98*10^{-2}}{1}=\frac{x}{2.5*10^9}$

Solve for "x":

$(2.5*10^9)(\frac{5.98*10^{-2}}{1})=x\\\\x=14.95*10^7$

To express this height in Scientific notation the decimal point must be after the first digit, so you must move it one place to the left:

$x=1.495*10^8$