. Computer keyboard failures can be attributed to electrical defects or mechanical defects. A repair facility currently has 25 failed keyboards, 6 of which have electrical defects and 19 of which have...

. Computer keyboard failures can be attributed to electrical defects or mechanical defects. A

repair facility currently has 25 failed keyboards, 6 of which have electrical defects and 19 of

which have mechanical defects.

(a) How many ways are there to randomly select 5 of these keyboards for a thorough

inspection (without regard to order)?

(b) In how many ways can a sample of 5 keyboards be selected so that exactly 2 have an

electrical defect?

(c) If a sample of 5 keyboards is randomly selected, what is the probability that at least 4 of

these will have a mechanical defect?