Worker Assignment Study
A factory has three machines and eight possible machine operators.
(a) How many distinct assignments (orderings) of machine operators to machines are possible?
(b) What is the probability of one particular ordering of machine operators to the three machines?
(a) Given n = 8 machine operators and r = 3 machines.
Then _{8} P_{3}=\frac{8!}{(8-3!)} =\frac{8!}{5!} =\frac{8\times 7\times 6\times 5\times 4\times 3\times 2\times 1}{5\times 4\times 3\times 2\times 1} = 336 permutations
There are 336 distinct assignments of 8 workers to 3 machines.
(b) The probability of selecting a particular grouping of three machine operators is:
P(particular order of 3 machine operators) = \frac{1}{336} = 0.00297 (0.297%)
Any particular ordering (where order of assignment to the three machines is important) has only a very small probability (only 0.297% chance) of being selected.