Q37 of 168 Page 7

The sum of the reciprocals of Rehman's age (in years) 3 years ago and 5 years from now is . Find his present age.

Let the present age of Rehman be x years.


So, 3 years age his age was = (x – 3) years


The reciprocal =


And, after 5 years the age will be = (x + 5) years


The reciprocal =


So, according to the question



Taking L. C. M. of (x – 3) and (x + 5)




6x + 6 = x2 + 2x – 15


x2 + 2x – 6x – 15 – 6 = 0


x2 – 4x – 21 = 0


x2 – 7x + 3x – 21 = 0


x(x – 7) + 3(x – 7) = 0


(x – 7)(x + 3) = 0


x = 7 and x = –3


x = – 3 is not possible because age cannot be negative.


So, x = 7


Therefore present age of Rehman is 7 years.


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