Go through the first part of the problem first. You know N=20. Then try n=0, 1, and 2 using what you know about calculating probabilities using binomial distribution.
It states 5% of all components are defective. So how many in a sample of 20 are defective? What is the probabilities of having 0 defectives? How about 1 and 2?
Here is a link in case: http://mathworld.wolfram.com/BinomialDistribution.html

thats the problem, i have no clue how to do binomial and when ever i look at it online it just blags my head, anyone help me with some step by step instructions on working it out?

Once you have read through the page, move on to your question. It is a lot like the problems on the page. The important step is to identify the variables. Try (i) - the probably of 0 being the number of defective samples. Thus x=0. You are taking 20 total samples, so n=20. You are also given the probability that 5% are defective. Now it is a matter of plugging everything in the formula.