John want to buy a $100 Trouser at the store, but he think it’s too expensive. Finally, it goes on sale for $20. What is the percent decrease?	Answers:	A) 20%	B) 30%	C) 40%	D) 70%	E) 80%
The is always the difference between our starting and ending points. In this case, it’s 100 – 20 = 80. The “original” is our starting point; in this case, it’s 100. (80/100)*100 = (0.8)*100= 
<gadget id="calculator">(0.8)*100</gadget>
<output>80</output>
80%.   80%
<result>E</result>
John want to buy a $100 Trouser at the store, but he think it’s too expensive. Finally, it goes on sale for $20. What is the percent decrease?