问几道SAT概率数学题
没学过高中概率,希望讲的详细一些.
1.Ifp,r,m,n,tandsaresixdifferentprimenumbersgreaterthan2,andn=p*r*s*m*n*t,howmanypositivefactors,including1andn,doesnhave?
2.Ifsomeonethrowsadicetwice,onthefirsttimehegetsapoints,andonthesecondhegetsbpoints,whatistheprobabilitya/b>1?
3.Mr.Jonesmustchoose4ofthefollowing5flavorsofjellybean:apple,berry,coconut,kumquat,andlemon,HowmanydifferentcombinationsofflavorscanMr.Joneschoose?
4.有5张卡片,其中的一张A永远都不在两边,问有多少种排列方式