Question 364 of 480
What is the result of simplifying the expression \( (3 \times 10^4) \times (2 \times 10^3) \) in standard form?
- \( 6 \times 10^7 \)
- \( 6 \times 10^6 \)
- \( 5.5 \times 10^7 \)
- \( 5.5 \times 10^6 \)
Correct Answer:
B
Explanation
To simplify the expression \( (3 \times 10^4) \times (2 \times 10^3) \) in standard form, let's break it down step-by-step.
### Step 1: Understand the Components
The expression consists of two parts:
- \( 3 \times 10^4 \)
- \( 2 \times 10^3 \)
Here, \( 3 \) and \( 2 \) are the coefficients, while \( 10^4 \) and \( 10^3 \) are the powers of ten.
### Step 2: Multiply the Coefficients
First, we multiply the coefficients:
\[
3 \times 2 = 6
\]
### Step 3: Add the Exponents
Next, we need to multiply the powers of ten. When multiplying numbers in scientific notation, we add the exponents:
\[
10^4 \times 10^3 = 10^{4+3} = 10^7
\]
### Step 4: Combine the Results
Now, we combine the results from Steps 2 and 3:
\[
(3 \times 10^4) \times (2 \times 10^3) = 6 \times 10^7
\]
### Final Answer
Thus, the simplified expression in standard form is:
\[
6 \times 10^7
\]
### Correct Option
The correct option is **A. \( 6 \times 10^7 \)**.
### Explanation of Other Options
- **B. \( 6 \times 10^6 \)**: This option is incorrect because it suggests that the exponent of ten should be \( 6 \) instead of \( 7 \). This would imply that we did not correctly add the exponents when multiplying the powers of ten.
- **C. \( 5.5 \times 10^7 \)**: This option is incorrect because it uses \( 5.5 \) as the coefficient instead of \( 6 \). The multiplication of the coefficients \( 3 \) and \( 2 \) gives \( 6 \), not \( 5.5 \).
- **D. \( 5.5 \times 10^6 \)**: This option is incorrect for the same reasons as options B and C. It incorrectly uses both the coefficient \( 5.5 \) and the exponent \( 6 \), which do not match the results of our calculations.
### Common Pitfalls
- **Forgetting to add exponents**: When multiplying powers of ten, always remember to add the exponents.
- **Incorrectly multiplying coefficients**: Ensure that you multiply the coefficients correctly; small mistakes can lead to incorrect answers.
- **Misinterpreting standard form**: Standard form requires that the coefficient is between \( 1 \) and \( 10 \). In this case, \( 6 \) is valid.
### Revision Summary
- To multiply numbers in scientific notation, multiply the coefficients and add the exponents.
- The expression \( (3 \times 10^4) \times (2 \times 10^3) \) simplifies to \( 6 \times 10^7 \).
- Always check your calculations for both coefficients and exponents to avoid common mistakes.
- The correct answer is **A. \( 6 \times 10^7 \)**.