A company knows from warranty claims that 2% of a particular product will be faulty. It would like to interview a purchaser of a faulty product to assess their user experience, so they randomly phone customers who have purchased this product. What is the probability that the first purchaser of a faulty product will be found on the 20th phone call?

Assume that whether a purchaser receives a faulty product is independent of all other purchasers, and give your answer to at least 3 decimal places.

Explain it clearly and need only typed ansers

Thank you