NO.PZ201812100100000506
问题如下：
Relative to its domestic tax rate, Triofind’s effective tax rate is most likely:
选项：
A. lower.
B. the same.
C. higher.
解释：
A is correct.
Norvolt exempts the non-domestic income of multinationals from taxation. Because Norvolt has a corporate tax rate of 34%, the 0% tax rate in Borliand and the fact that 25% of Triofind’s net income comes from Borliand should result in a lower effective tax rate on Triofind’s consolidated financial statements compared with Triofind’s domestic tax rate. Abuelio’s tax rate of 35% is very close to that of Norvolt, and it constitutes only 15% of Triofind’s net income, so its effect is unlikely to be significant.
解析：A国家税率是35%，和母公司所在国家税率相差不大，且A公司NI占比也较少（15%），所以A公司所在国家的税率对母公司的有效税率影响不大。N国家的企业税率是34%，B国家是0%，而且B公司的NI占了集团总NI的25%，占比大，而且还免税，对母公司的税收会有减轻的作用。
不考虑此题，请问effective tax rate 计算公式是什么
