How to do Business related math questions?

Tony buys a block of land for $120 500 and sells it within the same financial year for $135 800. A car worth $20 000 can be bought using a hire purchase contract for a deposit of $2500, with the balance being paid off over 5 years via monthly repayments. The simple interest rate applying to the contract is 8% pa. a How much profit does he make on the land? 0.5 mark a Find the balance (principal) still owed after the deposit has been paid. 0.5 mark Now using the following tax table: ub division T axable income %) of tax able Nil 19% 32.5% 37% 45% S18,200 18,201 -S37 7,001-580,000 b Find the interest which will be paid on the deal. 1.5 marks 001 -$180,000 1& Over b If Tony's other salary for the financial year is $76 850, how much capital gains tax will he pay on the profit he makes on the block of land? 2 marks Find the monthly repayments. 1.5 marks c Calculate total tax payable by Tony for the financial year 2.5 marks d Find the effective interest rate applicable to this contract, correct to one decimal place. 1.5 marks END OF TEST PAPER