问题如下：
The exchange rate between the Canadian dollar (CAD) and US dollar (USD) is 1.3245(CAD/USD=1.3245). Assume that the Canadian dollar (CAD) has appreciated 15 percent against US dollar (USD) during the past month. How much has the US dollar depreciated against the Canadian dollar?
选项：
A.15%
B.More than 15%
C.Less than 15%
解释：
C is correct.
考点：Percentage Change in A Currency
解析：A货币对B货币的升值幅度不等于B货币对A货币的贬值幅度。
在本题中，[1/(1 + 0.15)] – 1 = (1/1.15) – 1 = -0.1304, or -13.04%.
一开始是 1.3245 CAD/USD，那么即为(1/1.3245) USD/CAD，则appreciated后，为 (1/1.3245+15%) USD/CAD = 0.905 USD/CAD. 所以这个时候，CAD/USD为 1.10497，再来算美元贬值，不就是(1.10497-1.3245)/1.3245=- 16.6% 不应该就选B嘛？
