probability?

32.
(a)
A has two choices: A→B or A→D→E ,
so P( A→B ) = P( A→D→E ) = 0.5

P( DE )
= P( A→D→E )
= 0.5 ..... Ans

(b)
B has two choices: B→E or B→C→F ,
so P( B→E ) = P( B→C→F ) = 0.5

P( BE )
= P(B) * P( B→E )
= P( A→B ) * P( B→E )
= 0.5 * 0.5
= 0.25 ..... Ans

(c)
E has two choices: E→G or E→F ,
so P( E→G ) = P( E→F ) = 0.5

P( EG )
= P(E) * P( E→G )
= [ P(BE) + P(DE) ] * P( E→G )
= [ 0.25 + 0.5 ] * 0.5
= 0.75 * 0.5
= 0.375 ..... Ans

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2.ABEFH
3.ABEGH
4.ADEFH
5.ADEGH