The decimal equivalent of 1/20 upto three significant figures is

The correct option is 0.0500.

To find the decimal equivalent of the fraction $\frac{1}{20}$ up to three significant figures, we follow these steps:

Step 1: Convert the fraction to a decimal
Dividing 1 by 20 gives:
$\frac{1}{20}=0.05$

Step 2: Determine the significant figures requirement
We need to express this value to three significant figures. Let's look at the rules for significant figures in decimal numbers:
1. Leading zeros (zeros to the left of the first non-zero digit) are not significant. In 0.05, the zeros before the 5 are leading zeros and do not count.
2. The first significant figure is 5.
3. Trailing zeros in a decimal number (zeros to the right of the last non-zero digit) are significant because they indicate the precision of the measurement.

Step 3: Express the number with three significant figures
Starting from the first significant digit (5), we append trailing zeros to make a total of three significant figures:
- First significant figure: 5
- Second significant figure: 0
- Third significant figure: 0
Therefore, the value written to three significant figures is:
$0.0500$