The number of flaws on a magnetic tape produced continuously at a factory follows a Poisson distribution with an average of 0.01 falws per meter. A stand unit of this tape contains 250 meters of magnetic tape.

(a) What is the probability that there are at least two flaws in a single unit of tape?

(b) In a random sample of 20 units of tapes, what is the probability that at least two of them are flawless?

for part a I have 250x0.01=2.5 P(x>=2)=1-P(x=0)-P(x=1)=1-e^{-2.5}*2.5^0/0! -e^-2.5*2.5^1/1!

for part b, do I just times 2.5 by 20?