Can you help me solve this problem prom 3.1, 3.4 to 3.5?

Self-test problem 3.1 Rundle Lid has estimated sales for January to April as: S January 150 000 February 180 000 March 120 000 April 165 000 The mark-up on cost is 50% and management requires that opening stock be 90% of sales (at cost) each month. Required Prepare a purchases budget for the three months ending 31 March.Self-test problem 3.4 Refer to Self-test problem 3.1. Required Prepare a cost of goods sold budget for the three months ending 31 March.Self-test problem 3.5 Refer to Self-test problem 3.1. Rundle Ltd provides you with the following information relating to estimated expenses. Expense details Sales representatives' salaries $72 000 pa apportioned equally each month Cartage outwards 5% of sales Advertising 3% of sales General salaries and wages $144 000 pa apportioned equally each month Audit fees $2 400 pa apportioned equally each month Payroll on-costs (treated as an administration expense) 15% of total payroll Rent $43 200 pa apportioned equally each month Depreciation $27 600 pa apportioned equally each month Telephone $1 800 pa apportioned equally each month Stationery $1 800 pa apportioned equally each month Interest on loan January $830 February-$820 March-$810 Bank charges $720 pa apportioned equally each monthRequired Prepare the marketing expenses budget for the three months ending 31 March