The numberator of a rational number is 3 less than the denominator. If the denominator is increased by 5 and the numerator by 2, we get the rational number 1/2. Find the rational number.
Le the denominator is 
Numerator is 
Fraction = 
= 
According to the question:
Numerator is increased by 2 and Denominator is increased by 5, then fraction is 
On cross multiplication, we get
Therefore Denominator =7
Numerator = 
Therefore fraction = 
20