Question

Q5: A plant that produces brake pads is under inspection due to the excessive number of defective pads. The pads can be made on 12 seemingly identical machines, and a box containing 1 pad from each machine is brought to a quality assurance inspector to inspect. It is known that 2 out of the 12 machines are responsible for producing the defective pads. If the inspector samples 3 pads at random from the box, determine the following:

a) In how many ways can we get exactly 1 defective pad in a sample?

b) In how many ways can we get at least 1 defective pad in a sample?

Answer 1