The correct answer is: 0.3
Step-by-step explanation:
To write
of 3.0 in the decimal form, you have to divide 3.0 with 10 and evaluate as follows:

0.3
Now when we solve the fraction, we would get 0.3. Hence, the correct answer is 0.3.
Another Method:
The word "of" is translated mathematically as " * " (multiplication).
So
of 3.0 can be written as:

The same answer = 0.3!