Gross Profit Method
Presented below is information related to Aaron Rodgers Corporation for the current year.
Beginning Inventory			$ 600,000
Purchases			1,500,000
Total goods available for sale				$ 2,100,000
Sales revenue				2,500,000
Compute the ending inventory, assuming that
	a) gross profit is 45% of sales
	b) gross profit is 60% of cost
	c) gross profit is 35% of sales
	d) gross profit is 25% of cost

I'm having a really hard time understanding this. I clearly do not understand what the book is telling me versus what the question is asking. Any help would be appreciated.