问题如下：
You are building models for forecasting earnings per share of two construction companies, A and B. The probability that Company A's EPS will increase at the end of year is 0.45. The probability that Company B's EPS will increase at the end of year is 0.25. The probability that two companies' EPS both increase is 0.10. What is the probability that at least one of the two companies' EPS will increase according the forecasting models?
选项：
A.0.20
B.0.40
C.0.60
解释：
C is correct.
The probability that at least one of the two companies' EPS will increase=0.45+0.25-0.10=0.60
想问下这道题目，为什么是减去0.1，而不是加上0.1呢？因为感觉A和B两个同时发生，也是属于至少一个发生的范围里的吧？
