The fraction is

Solution:
Let the denominator of fraction be "a"
Given that numerator of a fraction is 1 less than the denominator
numerator of a fraction = denominator - 1
So the numerator of a fraction = a - 1
Thus the required fraction is:

Also given that if 4 is added to both the numerator and denominator the fraction becomes 8/4

Thus the original fraction is:

Thus the fraction is
