For every question, four probable answers bear in letters (A), (B), (C) and (D) are given. Only one out of these is correct. You have to choose the orrect answer.
The Product `0.4 xx0.04 xx 0.004` is

Options

A. 0.00064
B. 0.0064
C. 0.64
D. 6.4E-5

Answer

To solve the problem of finding the product \(0.4 \times 0.04 \times 0.004\), we can follow these steps:

### Step 1: Convert the decimals to fractions
We can express each decimal as a fraction:
- \(0.4 = \frac{4}{10}\)
- \(0.04 = \frac{4}{100}\)
- \(0.004 = \frac{4}{1000}\)

### Step 2: Write the product in fraction form
Now we can write the product as:
\[ 0.4 \times 0.04 \times 0.004 = \frac{4}{10} \times \frac{4}{100} \times \frac{4}{1000} \]

### Step 3: Multiply the fractions
To multiply the fractions, we multiply the numerators and the denominators:
\[ \text{Numerator: } 4 \times 4 \times 4 = 64 \]
\[ \text{Denominator: } 10 \times 100 \times 1000 = 1,000,000 \]
So, we have:
\[ \frac{64}{1,000,000} \]

### Step 4: Convert the fraction back to decimal
Now, we convert \(\frac{64}{1,000,000}\) back to decimal:
\[ \frac{64}{1,000,000} = 0.000064 \]

### Step 5: Express in scientific notation
We can express \(0.000064\) in scientific notation:
\[ 0.000064 = 6.4 \times 10^{-5} \]
This can also be written as \(6.4e^{-5}\).

### Conclusion
The correct answer from the options provided is:
**(D) \(6.4 \times 10^{-5}\)**.

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