arithmetic
When net salary is 10350 and 13.75% pf deducted how gross amount is calculated..
For eg: If gross salary is 12000, pf is 13.75% then
net salary= 12000* 13.75%
= 10350
But how to calculate reverse way wen we know net salary as 10350 and pf deduction as 13.75%
using simple formula
If $X$ is p% of the gross $\mathbf{G}$, then $$X = \frac{p}{100}\mathbf{G}.$$ Solving for $\mathbf{G}$, we have $$\mathbf{G} = \frac{100X}{p}.$$
For example if your net is $1000$, and this is 80% of your gross, then $$\text{Gross} = \frac{100(1000)}{80} = 1250.$$
As Listing says, there is no unique solution. One approach would be to plot tax paid against gross income, draw a smooth curve and estimate any interpolated values.
So for a gross income of $\$1000$, tax might be about $\$130$ i.e. about 13%.
If you are feeling brave, you might try to extrapolate outside the points you know (the tax on a gross income of $\$0$ might be $\$0$), but you are more likely to be wrong.
Best Answer
Hint
Let us call $N$ the net salary, $G$ the gross salary and $x$ the percentage corresponding to the pf deduction. So, you have $$N=G\times (1-\frac{x}{100})$$ This gives you the relation between the three quantities. From this, you can extract $G$ and get $$G=\frac{100 N}{100-x}$$