A box contains 100 copper plugs, 27 of which are oversize and 16 are under size. A plug is taken from the box, tested and replaced: a second plug is then similarly treated. Determine the probability that?

Question

a) Both plugs are acceptable.
b) The first plug is oversize and the second plug is undersize.
c) One is oversize and the other is under size.

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Answer 1 · 2018-04-24T13:39:06

a)#3249/10000#

b)#27/625#

c)#54/625#

Both acceptable is #57/100xx57/100=3249/10000#

Oversize then undersize is #27/100xx16/100=432/10000=27/625#

one over and one under is
#27/100xx16/100=432/10000=27/625# or

#16/100xx27/100=432/10000=27/625#

#=># as it can be either way around you add the probabilities

#27/625#+#27/625#=#54/625#