John want to buy a $100 Trouser at the store, but he think it’s too expensive. Finally, it goes on sale for $60. What is the percent decrease?
Pick one: A) 20% B) 30% C) 40% D) 50% E) 60%
The is always the difference between our starting and ending points. In this case, it’s 100 – 60 = 40. The “original” is our starting point; in this case, it’s 100. (40/100)*100 = (0.4)*100= 
<gadget id="calculator">(0.4)*100</gadget>
<output>40</output>
40%.   40%
<result>C</result>
John want to buy a $100 Trouser at the store, but he think it’s too expensive. Finally, it goes on sale for $60. What is the percent decrease?