1.Aconstructioncompanywaspaidatotalof$500,000foraconstructionproject.Thecompany’sonlycostsfortheprojectwereforlaborandmaterials.Wasthecompany’sprofitfortheprojectgreaterthan$150,000?
(1)Thecompany’stotalcostwasthreetimesitscostformaterials.
(2)Thecompany’sprofitwasgreaterthanitscostforlabor.
2.
Acertainrollercoasterhas3cars,andapassengerisequallylikelytorideinany1ofthe3carseachtimethatpassengerridestherollercoaster.Ifacertainpassengeristoridetherollercoaster3times,whatistheprobabilitythatthepassengerwillrideineachofthe3cars?
A.0
B.1/9
C.2/9
D.1/3
E.1
(答案为3×2×1=6,3×3×3=27,6/27)可是不是在三辆车中任选一辆吗?为什么第二次只能在两辆车中选了呢,第三次只能选一辆了呢?