Question 90 of 480
Evaluate \(\frac{(0.14^2 \times 0.275)}{7(0.02)}\) to 3 decimal places.
- A. 0.039
- B. 0.385
- C. 0.033
- D. 0.038
Correct Answer:
A
Explanation
To evaluate the expression \(\frac{(0.14^2 \times 0.275)}{7(0.02)}\) and find the correct answer among the options provided, we will break down the calculation step-by-step.
### Step 1: Calculate \(0.14^2\)
First, we need to square \(0.14\):
\[
0.14^2 = 0.14 \times 0.14
\]
Calculating this:
\[
0.14 \times 0.14 = 0.0196
\]
### Step 2: Multiply by \(0.275\)
Next, we multiply the result from Step 1 by \(0.275\):
\[
0.0196 \times 0.275
\]
To perform this multiplication, we can break it down:
\[
0.0196 \times 0.275 = 0.0196 \times \frac{275}{1000} = \frac{0.0196 \times 275}{1000}
\]
Calculating \(0.0196 \times 275\):
\[
0.0196 \times 275 = 5.390
\]
Now, dividing by \(1000\):
\[
\frac{5.390}{1000} = 0.00539
\]
### Step 3: Calculate the denominator \(7(0.02)\)
Now, we calculate the denominator \(7(0.02)\):
\[
7 \times 0.02 = 0.14
\]
### Step 4: Divide the results
Now we can divide the result from Step 2 by the result from Step 3:
\[
\frac{0.00539}{0.14}
\]
To perform this division, we can convert \(0.14\) to a fraction:
\[
0.14 = \frac{14}{100} = \frac{7}{50}
\]
Thus, we can rewrite the division as:
\[
\frac{0.00539}{0.14} = 0.00539 \div 0.14 = 0.00539 \times \frac{100}{14}
\]
Calculating \(0.00539 \times \frac{100}{14}\):
First, calculate \(\frac{100}{14}\):
\[
\frac{100}{14} \approx 7.142857
\]
Now multiply:
\[
0.00539 \times 7.142857 \approx 0.0384
\]
### Step 5: Round to three decimal places
Now we round \(0.0384\) to three decimal places:
\[
0.0384 \approx 0.038
\]
### Conclusion
The final answer is \(0.038\), which corresponds to option D.
### Explanation of Other Options
- **Option A (0.039)**: This is incorrect because our calculation showed that the result is \(0.0384\), which rounds to \(0.038\), not \(0.039\).
- **Option B (0.385)**: This is incorrect as it is significantly larger than our calculated value. It does not relate to the operations performed.
- **Option C (0.033)**: This is also incorrect as it is less than our calculated value. It does not reflect the multiplication and division performed.
### Revision Summary
- To evaluate expressions, perform operations step-by-step, ensuring accuracy at each stage.
- Always round your final answer to the required number of decimal places.
- Be cautious with multiplication and division, especially with decimals.
- Check each option against your calculated result to confirm correctness.