Question

If the sum of the reciprocals of a person A's ages (in years) 3 years back and 5 years from now is 1/3 Then his present age is
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Answer 1

so his current age is 7 yrs

Answer 2

Answer:

The present age is x=7 years

Step-by-step explanation:

Given : If the sum of the reciprocals of a person A's ages (in years) 3 years back and 5 years from now is 1/3.

To find : His present age ?

Solution :

Let his current age be x.

3 years back, his age is (x-3)

5 years ahead, his age is (x+5)

According to question,

$\frac{1}{x-3}+\frac{1}{x+5}= \frac{1}{3}$

$\frac{x+5+x-3}{x^2+5x-3x-15}= \frac{1}{3}$

$\frac{2x+2}{x^2+2x-15}= \frac{1}{3}$

$6x+6=x^2+2x-15$

$x^2-4x-21=0$

$x^2+3x-7x-21=0$

$x(x+3)-7(x+3)=0$

$(x+3)(x-7)=0$

$x=-3,7$

Age cannot be negative, so, reject x=-3

The present age is x=7