From the salary of an officer, 10% is deducted as house rent, 20% of the rest, he spends on conveyance, 20% of the rest he pays as income tax and 10% of the balance, he spends on clothes. Then, he is left with Rs. 15552. Find his total salary.

Let the total salary be Rs. $$x$$
Then,
(100 -10)% of (100 - 20)% of (100 - 20)% of (100 - 10)% of $$x$$ = 15552
$$ \Leftrightarrow \left( {\frac{{90}}{{100}} \times \frac{{80}}{{100}} \times \frac{{80}}{{100}} \times \frac{{90}}{{100}} \times x} \right)$$       $$ = 15552$$
$$\eqalign{ & \Leftrightarrow x = \left( {\frac{{15552 \times 10000}}{{64 \times 81}}} \right) \cr & \Leftrightarrow x = 30000 \cr} $$