can someone please help in understanding how to do these problems?

Report all currencies to the nearest penny and all percentages to the nearest tenth. 1-2. Calculate the planned purchased at (1) retail and (b) cost given the following data: May Sales Markdowns BOM stock for May BOM stock for June Planned markup $18,000 $2,550 $32,000 $41.000 52% 3. If planned sales for July are $75,000 and the stock-sales ratio is planned at 2.5, the calculate BOM stock (2pts). 4. If a department has the following figures, calculate the GMROII (2pts): Net sales $38,500 Stock turn 2.5 Gross margin 43% Markup 50%