Let A, B, and C be three events in a sample space , such that P(A) =

Let A, B, and C be three events in a sample space Ω, such that P(A) = 2P(B)

and P(B) = 2P(C). If in addition we have A = (B ∪ C)′, then the probability of the event A is

(a) 1∕7 (b)2∕7 (c)4∕7 (d)1∕2 (e)3∕5.