The numerator of a fraction is one less than the denominator. If 6 is added to the numerator, the fraction will be equal to $$\frac{5}4.$$​ Find the fraction.

Correct option is B

Given : 

The numerator of a fraction is one less than the denominator.

Solution:

Let's assume the denominator of the fraction  =  x.

The numerator = x-1.

So, the fraction is : 

$$\frac{x-1}{x}$$​

According 6 is added to the numerator: 

Then;

$$\frac{(x-1)+6}{x}$$ = $$\frac{5}{4}$$​​

$$\frac{x+5}{x}$$​ = $$\frac{5}{4}$$​

5x =  4(x + 5) 

5x = 4x + 20 

 x = 20

Denominator = 20 
Numerator  = x - 1

= 20 - 1 

= 19​

The fraction is  $$\frac{19}{20}$$  

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