Question 1128088
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This problem is for MENTAL solution.


<pre>
    From the condition, an attentive reader may conclude IMMEDIATELY (without writing equations) that

    the price of one refill is  $9.35 - $8.40 = $0.95.


    Then the next step (which also can be done mentally) is to calculate the price of the egg breakfast as  

        $8.40 - 2*$0.95 = $8.40 - $1.90 = $6.50.
</pre>

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The problems of this kind are traditionally considered as the mental problems, &nbsp;so, &nbsp;in my view, 
the instructions that accompany the problem in the post, &nbsp;badly serve to the students' education in Math.


Again, &nbsp;problems like this one are traditionally considered as the tool to develop students' ability to solve them MENTALLY.