Explanations:
Let the numerator of the fraction be x and let the denominator be y.
Hence, the original fraction is:

It is given that the denominator is 3 more than the numerator. It follows that:

It is also given that when both the numerator and denominator are increased by 4, the new fraction is equal to 3/4. This implies mathematically to the equation:

Simplify this equation:

Substitute y=x+3 into this equation:

Solve the equation for x:

Substitute x=5 into the equation y=x+3:

Hence, x=5, and y=8.
It follows that the original fraction is 5/8.
Answer:
The original fraction is 5/8.