Here is another way to do the problem without using decimals to clear the equations of fractions. Remember, order of operations and work from the left side of the equation to the right side.
1/1000:1/50 is actually a complex fraction where you have a fraction in the numerator and a fraction in the denominator. It can also be written as:
1/1000 divided by 1/50 = x/6
You must continue to simplify the left hand side of the equation before you can do anything with the right side of the equation. Next, rewrite it as 1/1000 x 50/1 (this is how you divide a fraction in the numerator by a fraction in the denominator) and set it equal to x/6. Your new equation is:
1/1000 x 50/1 = x/6
Continue simplifying the left side to get the new equavalent ratio:
50/1000 = x/5 which simplifies to 1/20 = x/6
Now, solve by cross multiplying:
20x = 6, which simplifies to x = 6/20 or 3/10
Since the problem was originally given with fractions, the answer should also be expressed as a fraction, rather than a decimal. Although 0.03 would also be considered a correct answer it may not have been one of your answer choices.