Mr$.$ Khaled has been working for $10$ years at Al$-$Salam Co$.$ and is currently employed as a senior engineer. His current$/$latest benefit package includes the followings;

$$ Current monthly $(20-$day working$)$ gross salary of $$15,000,$ which is assumed to be same throughout the year.

o $\%50$ extra payment if he works on Saturdays, which is always available.

o $\%100$ extra payment if he works on Sundays, which is always available.

$$ Yearly one$-$month $(20-$day working$)$ paid vacation.

$$ Full coverage family health insurance, which is financially equal to $$30,000/$year$.$

$$ One$-$month gross salary $($based on the latest figure$)$ per year completion as indemnity.

His current contract offers a yearly salary increase $\%10$ higher than the inflation rate. The country has a personal income tax scheme of $$50,000$ tax$-$exempt, $\%10$ if the yearly gross income is between $$50,000$ and $$100,000,$ and $\%20$ if it is between $$100,000$ and $$250,000,$ and finally $\%30$ if it is greater than $$250,000.$

Mr$.$ Khaled thinks that he has enough experience and should do his own business, opening up his own consulting firm. He estimates that he needs $$500,000$ for starting up his business. He has $$200,000$ on his investment$/$savings account, which earns yearly $\%2$ higher than inflation rate and he will use his all savings and get $3-$year murabaha $($loan$)$ of $$300,000$ from his financial institution to open up his business. He will pay back $$100,000$ principle each year and the current $($first$)$ year$$s pre$-$determined financing rates will be $\%25,$ but it will increase to $\%30,$ and $\%40$ in the following years respectively according to the contract.

As stated by his employment contract, if he quits his job before completing $15$ years, $\%50$ of his indemnity will be cut. Furthermore, if he starts his business, due to the business nature, he will have $7$ days weekly work and based on this, his projected revenues during the $3-$year period of operation are $$1,000,000,$ $$1,500,000,$ and $$2,000,000.$

On the other hand, his expected expenses for the first year are as follows;

$$ Monthly total salaries to employed people are $$80,000.$

$$ Yearly supplies and equipment expenses are $$150,000.$

$$ He has $$600,000$ rent contract of $3$ years, each year of $$200,000$ for the office. The rent will be fixed for $3$ years.

$$ Monthly total utilities are $$10,000.$

$$ One$-$time license and certification from the government is $$25,000.$

$$ The country has a business income tax scheme of no income tax until $$100,000.$ However, it will be $\%10$ between $$100,000$ and $$250,000$ and $\%20$ between $$250,000$ and $$500,000,$ and $\%30$ if it is greater than $$500,000.$

$$ Yearly expected inflation rate is $25\%$ and $30\%$ respectively for the following two years. Thus, all expected expenses are projected to increase with inflation rate if not mentioned otherwise.

Based on the assumptions and projections given above;

a$)$ Calculate the explicit cost of each year for three years of opening up his own business.

b$)$ Calculate the implicit cost of each year for three years of opening up his own business.

c$)$ Calculate the business profit of each year for three years of opening up his own business.

d$)$ Calculate the economic profit of each year for three years of opening up his own business.

e$)$ Briefly discuss whether Mr$.$ Khaled should quit his current job and start his own business based on the three$-$year projection.

f$)$ Raise an argument against your answer in e$.$ What might change the answer you gave in e$?$ Briefly discuss.