Question

There are three very old X-ray security machines in the departure complex of an airport.

All three machines are exactly the same. The probability that a machine breaks down in

the course of a day is 0.2. If they are all in working order at the beginning of a day, and

breakdowns are independent of each other, find the probability that during the day: use

binomial – success or failure

(a) there are no breakdowns=0.512 =3C0*.20*.83

(b) one machine breaks down=0.384=3C1*.21*.82

(c) two machines break down=0.096=3C2*.22*.81

(d) all three machines break down=0.008=3C3*.23*.80

Answer 1