You need three tools for this job. Let's make sure you remember how to use them:
#1). 3 is the same thing as 3/1
#2). When you need to divide fractions, turn the second one upside down, and then multiply them.
#3). When you're multiplying fractions, multiply the numerators to get the numerator of the answer, and multiply the denominators to get the denominator of the answer.
Those are the tools you need to solve this problem.
1). 3/4 divided by 3 is the same as 3/4 divided by 3/1 .
2). To divide by 3/1, multiply by 1/3 .
Now you have 3/4 times 1/3 .
3). That's the same as (3 x 1) / (4 x 3) = 3/12 =<em> 1/4</em>