Mohamad bought his home in 2010 and commenced operating a business from his home. He has a large office which occupies 15% of the house. Mohammad does not own any other property.
Mohammad estimates that 15% of his electricity and gas heating was used for the business in 2018-2019.
During each of the 2017-2018 and 2018-2019 financial years Mohammad had the following expenses in respect of the house:
Gas heating$ 750
Electricity$ 5,000
Rates and taxes$ 3,000
Mortgage repayments
Interest$10,000
Capital repayments$ 4,000

On 1 July 2018 one of Mohammad’s corporate clients unexpectedly made an offer to purchase the business for a good price. Included in the offer was ongoing employment for Mohammad and a workspace in the Adelaide office. Mohammad accepted the offer and immediately commenced his new role as an employee.

While he worked in the Adelaide office most days, Mohammad continued to work from his home office two days each week. He estimates that 7% of his electricity and gas heating was running while he worked in his home office whilst undergoing his new employment.

Required:
a) Advise Mohammad what expenses he can claim for the 2017-2018 financial year
b) Advise Mohammad what expenses he can claim for the 2018-2019 financial year
c) Assume that instead of selling his business Mohammad sold his house on 1 July 2019, making a capital gain of $100,000. Would all of that gain be assessable? Why or why not?

In your response give reasons and refer to sections of legislation and cases, where relevant.