Let the earnings of A and B be Rs. $8x$ and $9x$ respectively.
A's new earnings after 50 % increase = $8x + \frac{50}{100} \times 8x = 12x$
B's new earnings after 25 % decrease = $9x - \frac{25}{100} \times 9x = \frac{27x}{4}$
=> Required ratio = $\frac{12x}{\frac{27x}{4}}$
= $\frac{16}{9}$ , which is already given.
Thus, we cannot determine A's earnings.