Question 1142141
<pre>
AGE           BROTHER
8              youngest
8+d            younger middle
8+2d           older middle
17             oldest
</pre>


{{{highlight_green(8+3d=17)}}}

{{{3d=17-8}}}

{{{3d=9}}}

{{{highlight_green(d=3)}}}-----------age difference between two successive brothers



youngest middle,  11
older middle,  14