From the salary of a person 10% is paid for house rent. 15%of the rest of the amount was spent on provisions and 10% of the remaining amount was spent for children’s education. After this expenditure. if he is left with Rs. 24786/-, then his salary in rupees is

Let his salary was Rs x.

Amount paid for the house rent $$=0.1 x$$Rs.

Amount spent on the provisions $$\dfrac{90x}{100}\times \dfrac{15}{100}=0.9\times 0.15x$$

Amount spent on the children's education $$=\dfrac{0.90\times 0.85 x\times 10}{100}=0.9\times 0.85\times 0.1 x$$

The left amount $$=24786Rs.$$

Hence, his salary $$0.1x +0.9\times 0.15x+0.9\times 0.85\times 0.1 x+24786=x$$

$$\Rightarrow 0.3115x+24786=x$$

$$\Rightarrow x-0.3115x=24786$$

$$\Rightarrow 0.6885 x=24786$$

$$\Rightarrow x=\dfrac{24786}{0.6885}=36000 Rs.$$