问题如下：
Purple Fleur S.A., a retailer of floral products, reported cost of goods sold for the year of $75 million. Total assets increased by $55 million, but inventory declined by $6 million. Total liabilities increased by $45 million, and accounts payable increased by $2 million.The cash paid by the company to its suppliers is most likely closest to:
选项：
A.$67 million.
B.$79 million.
C.$83 million.
解释：
A is correct.
Cost of goods sold of $75 million less the decrease in inventory of $6 million equals purchases from suppliers of $69 million. The increase in accounts payable of $2 million means that the company paid $67 million in cash ($69 million minus $2 million).
解析：考点是直接法下cash paid to suppliers的计算。由于是现金流的流出所以我们都在前面加一个负号，- Cash paid to suppliers= - COGS –Δinv + ΔA/P + Depreciation included in COGS，本题没有Depreciation included in COGS，所以- Cash paid to suppliers= - COGS –Δinv + ΔA/P=－75－（-6）+2=－67，负号代表是流出，所以付给供应商的钱是67块。
total assets total liability的变化量是干扰信息吗？做题的时候该用怎样的思路来识别判断呢？
