20.96 rounded off to 3 significant figures is

Options

A. (a)`21.0`
B. (b)20
C. (c)`21.1`
D. (d)20.9

Explanation

To round off the number 20.96 to three significant figures, we follow these steps:

### Step 1: Identify the significant figures
In the number 20.96, the significant figures are the digits that contribute to its precision. The significant figures here are:
- 2
- 0
- 9
- 6

Since we need to round to three significant figures, we will focus on the first three digits, which are 2, 0, and 9.

### Step 2: Determine the digit to be rounded
The third significant figure in 20.96 is 9. The next digit (the fourth significant figure) is 6.

### Step 3: Apply rounding rules
According to rounding rules, if the digit following the last significant figure (in this case, the digit 6) is 5 or greater, we round up the last significant figure. Since 6 is greater than 5, we will round up the 9.

### Step 4: Perform the rounding
When we round up 9, it becomes 10. However, since we are rounding within the context of significant figures, we need to carry this over to the preceding digit:
- The 2 becomes 3 (since 2 + 1 = 3), and we drop the 0 and 6.

Thus, we get:
- The rounded number is 21.0.

### Step 5: Write the final answer
Therefore, 20.96 rounded off to three significant figures is **21.0**.

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