Question 1- Robert is paid a base salary of $13,000 per year. In addition to this salary, he receives commission on sales exceeding $9,000. His total salary for last month was $2,500 and his sales were $13,750. Calculate his commission rate.

Question 2- Robert is paid a base salary of $13,000 per year. In addition to this salary, he receives commission on sales exceeding $9,000. His total salary for last month was $2,500 and his sales were $13,750. Calculate his commission rate.

Question 3- Last month, a 770 g box of cereal was sold at a grocery store for $3.20. However, this month, the cereal manufacturer launched the same cereal in a 650 g box, which is being sold at $2.80. What is the percent change in the unit price?

Question 4- Sarah purchased a microwave in Manitoba and received a receipt for the purchase. When she reached home, she noticed that most of the numbers on the receipt were faded, except for the PST (8%) amount of $35. Calculate the cost before taxes, GST (5%), and total cost of the microwave.

4) a. What is the cost before taxes?

4) b. What is the GST?

4) c. What is the total cost of the microwave?