Question 1138855
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The answer is  85 + 50 - 120 = 135 - 120 = 15.



<U>Explanation</U>


I do not need to explain why I added 85 and 50 - it is clear.


I need only to explain why I subtracted 120.


    It is because when I added 85 and 50, I exceeded the value of 120.


    I exceeded it exactly by the value of those who study both languages.


    Therefore, when I subtracted 120, I exactly got the number of those who study both languages.
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Answered, solved, explained and completed.


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See the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/misc/Counting-elements-in-sub-sets-of-a-given-finite-set.lesson>Counting elements in sub-sets of a given finite set</A>

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