Question:
The denominator of a rational number is greater than its numerator by 7. If the numerator is increased by 17 and the denominator decreased by 6, the new number becomes 2. Find the original number.
Solution:
Let the numerator be $\mathrm{x}$.
The denominator is greater than the numerator by 7 .
$\therefore(\mathrm{x}+7)$
$\therefore \frac{x+17}{(x+7)-6}=2$
$\Rightarrow \frac{x+17}{x+1}=2$
$\Rightarrow x+17=2(x+1)$ (by cross multiplication)
$\Rightarrow x+17=2 x+2$
$\Rightarrow x-2 x=2-17$
$\Rightarrow-x=-15$
$\Rightarrow x=15$
Therefore, the numerator is 15 .
$\text { Denominator }=(\mathrm{x}+7)=(15+7)=22$
$\therefore$ Original number $=\frac{15}{22}$