Question #e8654

1 Answer
Feb 18, 2017

#P("both work") = 1/15#

#P("at least 1 fail")=14/15#

Explanation:

Fractions are represented as parts of the whole of something. Consequently if you add up all the parts you should get a whole. The whole is expressed as 1. In that you may have 1 of a count of population of this country. So splitting the population into two equal counts is #1/2# of the population. That is #1/2# of 1 population.

So the sum of all probabilities is 1.
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Tony B

#P("Both work") = 2/6xx1/5=1/15#

#P("At least 1 fail") = #1 - probability all good # = 1-1/15=14/15#

The logic hear is that if there is at least 1 bad then it is not possible to have all good. So you remove the all good #->1-1/15=14/15#