【#GRE留开云kaiyun(中国)外语考试# #GRE数开云kaiyun(中国)考点：AT least One#】开云kaiyun(中国)习是一个长期坚持的过程，每天进步一点点，基础扎实一点点，日积月累，考试就会更容易一点点。以下为“GRE数开云kaiyun(中国)考点：AT least One”，欢迎阅读参考！更多相关讯息请关注©无忧考网！
AT least One
If probability of event A happening is p and event B happening is q, then
the probability that at least one of them happens is (p+q).
Example:
There are 20 quarters, 33 nickels, and 47 pennies in a jar. The probability
that a randomly selected coin is a quarter= 20/(20+33+47)=20/100=0.2 and the
coin is nickel = 33/100 =0.33.The probability it is either a quarter or a nickel
= 0.2+0.33=0.53.
Remember:
The events needs to be mutually exclusive, that is if one happens the other
cannot happen: a coin is either a quarter or nickel but not both.
