# Question: there are two machines at a factory that are used...

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There are two machines at a factory that are used for printing high quality posters of the periodic table. Machine 1 prints 70% of the posters produced by the factory and machine 2 the remaining 30%. On occasion, each machine omits the last column of elements; the probability of this happening is 0.06 for machine 1 and 0.13 for machine 2.

i. What is the probability that a poster printed at the factory will have the last column of elements omitted?

ii. Given that a poster printed at the factory has the last column of elements omitted, what is the probability that is was printed by machine 1?