Sunday, 31 March 2013

A fraction becomes 1/3 when 1 is subtracted from the numerator and it becomes 1/ 4 when 8 is added to its denominator. Find the fraction.


A fraction becomes 1/3 when 1 is subtracted from the numerator and it becomes 1/ 4 when 8 is added to its denominator. Find the fraction.
Let fraction is x/y
A fraction becomes 1/3 when 1 is subtracted from the numerator
So that
Cross multiply we get
3x -3  = y                    …(1)
and it becomes 1/ 4 when 8 is added to its denominator
so that
4x = y + 8
Plug the value of y from equation first we get
4x = 3x – 3 + 8
X = 5
Plug this value back in equation first we get
3*5 – 3  = y
15 – 3 = y
12 = y
Hence fraction is x/y = 5/12

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