among 18 computers, 12 are in working order and six are defective. How many sample of 4 are possible, selected without replacement and without regard to order, wherein all are defective?

Guest Aug 7, 2017

2+0 Answers




Since we know beforehand that we're only choosing amongst the defective ones, we want to choose any four of the six defectives  = C(6,4)  = 15 possible different samples of defectives



cool cool cool

CPhill  Aug 7, 2017

 We have 10 computers. 5 are taken, meaning being used, while the others are open. How many are open? If we bought 100 more computers, and the 5 that are being used were still used, how many computers would be open? 

Guest Aug 7, 2017
edited by Guest  Aug 7, 2017

16 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details