Question

In a given year, about 1.52×10^10
pieces of first-class mail are delivered in the U.S. If each piece of mail carries a stamp costing $0.55, what is the total cost in dollars to deliver all the pieces? Write the answer in scientific notation, expressed to the exact decimal place.

Answer 1

To find the total cost of delivering all the pieces of mail, we multiply the number of pieces of mail by the cost of each stamp.

Given:
- Number of pieces of first-class mail = \( 1.52 \times 10^{10} \)
- Cost of each stamp = \$0.55

Now we calculate the total cost:

\[
\text{Total Cost} = \text{Number of Pieces} \times \text{Cost per Stamp}
\]

\[
\text{Total Cost} = (1.52 \times 10^{10}) \times 0.55
\]

To perform the multiplication, we can multiply the coefficients (1.52 and 0.55) and then adjust for powers of 10:

\[
1.52 \times 0.55 = 0.836
\]

Now, we include the power of 10:

\[
\text{Total Cost} = 0.836 \times 10^{10}
\]

To express this in scientific notation, we need to adjust the coefficient to be between 1 and 10. Thus, we rewrite \( 0.836 \) as \( 8.36 \times 10^{-1} \):

\[
0.836 \times 10^{10} = 8.36 \times 10^{-1} \times 10^{10} = 8.36 \times 10^{9}
\]

Therefore, the total cost in scientific notation is:

\[
\boxed{8.36 \times 10^9}
\]