i dont know tbh

#include<stdio.h>

int totalgross, minustax, deduction, netincome;

int grossInc(int hours, int gross)
{
    totalgross=hours*gross;
    return totalgross;
}

int taxPay()
{
    if(totalgross>=4000)
    {
    minustax=totalgross*0.4;
    return minustax;
    }
    else if(totalgross>=3000 && totalgross<3999)
    {
    minustax=totalgross*0.3;
    return minustax;
    }
    else if(totalgross>=2000 && totalgross<2999)
    {
    minustax=totalgross*0.2;
    return minustax;
    }
    else if (totalgross>=1000 && totalgross<1999)
    {
    minustax=totalgross*0.1;
    return minustax;
    }
    else if (totalgross<1000)
    {
        minustax=totalgross*0.05;
        return minustax;
    }

}

int totalDed()
{
    deduction=minustax+100+100+100;
    return deduction;
}

int finalIncome()
{
    netincome=totalgross-deduction;
    return netincome;
}