Please calculated the answer in a correct, precise, and comprehensive manne along with relevant formulas. Thanks

$($a$)$ A project generates revenues of $1,000$ has cash expenses of $600$ and depreciation charges of $200$ in a particular year. The firm's tax rate is $35\%.$

Calculate the firm's net income.

$($b$)$ You have been asked to evaluate a project. After completion, the project lies dormant for two years before it generates an income stream. The first year of income is $200,000.$ The second year it rises to $300,000.$ By the third year it has reached $500,000.$ It stays at this level for $3$ years and then the project is scrapped with a zero value.

Calculate the profitablity of the project assuming that the rate of return is $10\%$ per

annum.