First we calculate expectation of Poisson distribution which is given as :
λ = n p
Here n = 20 and p = 0.1
So λ = 2..
Hence P(X <= 2) where X is no of pens picked = e-2 ( 20 / 0! + 21 / 1! + 22 / 2!)
= e-2 ( 1 + 2 + 2)
= 5 / e2
= 0.677
Hence P(X > 2) = 1 - 0.677 = 0.323
Hence 0.323 should be correct answer..