Apply percentage increase or decrease in various contexts, e.g. inflation of costs and wages, percentage mark-ups and discounts, percentage profit and loss, GST, simple interest.  𝐼 = 𝑃𝑖𝑛 where 𝐼 is simple interest, 𝑃 is principal, 𝑖 is interest rate per year and 𝑛 is number of years

A furniture retailer purchased office desks and chairs for resale. The table below shows the purchase price, mark-up percentage, and the number of units sold for each item. After three months, the retailer deposited the total profit from these sales into a savings account earning simple interest at \(3.6\%\) per annum. (a) Calculate the selling price of one desk. (1 mark) (b) Calculate the total profit from selling all desks and chairs. (2 marks) (c) Using the formula \(I = Pin\), calculate the simple interest earned on the total profit after \(2.5\) years. Give your answer to the nearest cent. (1 mark)

A furniture store purchases a dining table for $\$420$. The store applies a mark-up of $65\%$ to calculate the selling price. What is the selling price of the dining table?

A hardware store purchases power tools at a cost of $\$850$ per unit. The store marks up the price by $35\%$ to cover overheads and profit. (a) Calculate the selling price of each power tool. (1 mark) (b) During a sale, the store offers a discount of $15\%$ on the marked-up price. Calculate the sale price, to the nearest cent. (1 mark) (c) Calculate the actual profit the store makes on each tool sold during the sale, as a percentage of the original cost. (1 mark)