What is the number of significant figures in `0.310xx10`

Options

A. (a)`6`
B. (b)`4`
C. (c)`3`
D. (d)`2`

Answer

To determine the number of significant figures in the number \(0.310 \times 10\), we will analyze the number step by step.

### Step 1: Identify the number
The number given is \(0.310\). The multiplication by \(10\) does not affect the count of significant figures, so we will focus on \(0.310\).

### Step 2: Count the significant figures
Significant figures are counted based on certain rules:
1. All non-zero digits are considered significant.
2. Any zeros between significant digits are also significant.
3. Leading zeros (zeros before the first non-zero digit) are not significant.
4. Trailing zeros in a decimal number are significant.

In the number \(0.310\):
- The digit '3' is significant (non-zero).
- The digit '1' is significant (non-zero).
- The digit '0' is significant because it is a trailing zero in a decimal number.

### Step 3: Total significant figures
Now, we count the significant figures:
- '3' → 1 significant figure
- '1' → 1 significant figure
- '0' → 1 significant figure

Adding them up, we have a total of \(3\) significant figures in \(0.310\).

### Conclusion
Thus, the number of significant figures in \(0.310 \times 10\) is **3**.