Question 1209753
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my  brother is 7 years younger than me.  Twice my age plus 3 times his age is 99.
What are our ages? Plz use the singapore model method. 
I have the answer but can not understand how to show the working out using the bar model.
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        This problem can be solved MENTALLY, without using any equations,

        based on common sense ONLY.



<pre>
Mentally, reduce your age by 7 years, to the age of your brother.

Then "twice my age plus 3 times his age" will become 99 - 2*7 = 85.


Now this "twice my age plus 3 times his age" is the same as 5 times the brother age.


Hence, the brother age is 85/5 = 17 years, and your real age is 7 years more, or 17+7 = 24 years.


<U>ANSWER</U>.  You are  24 years old. Your brother is 17 years old.
</pre>

Solved mentally, in extremely simple way.


I believe that this solution is accessible for a 4-th grade student.