The salaries of Vipin and Dinesh are in the ratio 5 : 8. If the salary of each is increased by 4,800, then new ratio becomes 7 : 10. What is Vipin's salary?

Let the salary of Vipin and Dinesh be 5$$x$$ and 8$$x$$
$$\eqalign{ & \frac{{5x + 4800}}{{8x + 4800}} = \frac{7}{{10}} \cr & \Rightarrow 50x + 48000 = 56x + 33600 \cr & \Rightarrow x = \frac{{14400}}{6} \cr & \Rightarrow x = 2400 \cr} $$
∴ Vipin's salary is Rs. 12000