Answer:
4.74 hours
Step-by-step explanation:
Given that both person have to place same number of rivets that is
11209
first person take 9 hours to complete the work
hence 1 hour work of 1st person is
of total work
second person takes 10 hours to complete the same work
hence 1 hour work of 2nd person is 
Now if both work together then
1 hour work of both person =
=
thus working together they need
hours = 4.74 hours to complete the whole work which is placing 11209 rivets
In accordance with <em>propositional</em> logic, <em>quantifier</em> theory and definitions of <em>simple</em> and <em>composite</em> propositions, the negation of a implication has the following equivalence:
(Correct choice: iii)
<h3>How to find the equivalent form of a proposition</h3>
Herein we have a <em>composite</em> proposition, that is, the union of <em>monary</em> and <em>binary</em> operators and <em>simple</em> propositions. According to <em>propositional</em> logic and <em>quantifier</em> theory, the negation of an implication is equivalent to:
To learn more on propositions: brainly.com/question/14789062
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