In the state of Wisconsin, the sales tax on purchased items is a fixed percent rate of 5%. The table below shows a sales tax for a purchase of $900. PART A Determine the sale tax ($) for a $1,700 purchase. Use the sales tax percent of 5%. Use the appropriate equation or your own percent method to explain your work.

part b :

determine the purchase amount of the sales tax ($) is $ 105. use the sales tax percent of 5%. Use the appropriate equation or your own percent method to explain your work.

part c.

your classmate says that the sales tax percentage rate is 20% because 900 ÷45=20

state whether you agree or disagree with your classmates reasoning and use mathematics to explain your answer ​