题目
The price of an item was increased by 20 percent. The new price of the item was decreased by x percent, resulting in a final price that is 28 percent less than the original price.
选项
A.The quantity in Column A is greater.
B.The quantity in Column B is greater.
C.The two quantities are equal.
D.The relationship cannot be determined from the information given.
解析
设原价为 P 。
价格上涨20%后,变为:P × (1 + 20/100)
再下降 x%,价格变为:P × (1 + 20/100) × (1 - x/100)
该价格比原价低28%,即等于:P × (1 - 28/100)
因此,
P × (1 + 20/100) × (1 - x/100) = P × (1 - 28/100)
1 - x/100 = 0.72/1.2 = 0.6
x = 40
所以,答案为B。