The product will come even when at least one time an even number comes in n rolls.
P(even in 1 roll) =P(odd in 1 roll) =3/6 =1/2
P(atleast one time even in n rolls) = 1 - P(all times odd in n rolls) = 1 - 1/2^{n}
Hence ,the correct answer is 1 - 1/2^{n }
Option (e) None of the above ,is the ans.