You may know that income tax calculations in most parts of the world is based on slab model. Let's take a simple case of a two slab model with trandingre from base slab to top slab defined by slab amount $($S$)$ Let the base tax for gross income amount $($G$)$ equal to $($S$),$ be defined as $($BT$).$ If income exceed $S$ then the total tax would be

$T=(G-S)+\frac{T}{100}+BT$

where

I $-$ income tax percentage rate for income amount exceeding slab amount $($S$)$

$($eri us say hypothetically, a new scheme has been introduced to give a tax rebate as follows:

$=\frac{T}{G}$

Then, the final tax,

$F=T=B$

Qle leer income $(N)$ would be