MegaMart collects a sales tax equal to 1/16 of the retail price of each purchase and sends this money tp the state government.

a. Is the amount of tax collected proportional to the cost of an item before tax is added?

b. Is the amount of tax collected proportional to the cost of an item after tax has been added?

yes, yes

Tax=1/16* price
cost=tax+price=1/16 price+price=17/16* price

I still don't understand, can you explain more detail? and why it became 17/16*price?

0.5cm=1.5m

Yes,yes :)

i don't understand i need to show work..HELP

Is the amount of tax collected proportional to the cost of an item after tax has benn added? Explain?

Yes and yes because all of the ratios between the quantities are the same - which is 16/1 in your case.