【#GRE留學(xué)外語考試# #GRE數(shù)學(xué)考點(diǎn)：AT least One#】學(xué)習(xí)是一個(gè)長(zhǎng)期堅(jiān)持的過程，每天進(jìn)步一點(diǎn)點(diǎn)，基礎(chǔ)扎實(shí)一點(diǎn)點(diǎn)，日積月累，考試就會(huì)更容易一點(diǎn)點(diǎn)。以下為“GRE數(shù)學(xué)考點(diǎn)：AT least One”，歡迎閱讀參考！更多相關(guān)訊息請(qǐng)關(guān)注©無憂考網(wǎng)！

　　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.