Question

4: Commemorative coins are being struck at the local foundry. A gold blank (a solid

gold disc with no markings on it) is inserted into a hydraulic press and the obverse design is pressed

onto one side of the disc (this step fails with probability 0.15). The work is examined and if the

obverse pressing is good, the coin is put into a second hydraulic press and the reverse design is

imprinted (this step fails with probability 0.08). The completed coin is now examined and if of

sufficient quality is passed on for finishing (cleaning, buffing, and so on). Twenty gold blanks are

going to undergo pressing for this commemorative coin. Assume that all pressings are independent

of each other.

Answer 1