Question 1205422
<pre>

{{{system(3h+2d<=35,h+d>=13,d=7)}}}

{{{system(3h+2(7)<=35,h+(7)>=13,(7)=7)}}}

{{{system(3h+14<=35,h>=6)}}}

{{{system(3h<=21,h>=6)}}}

{{{system(h<=7,h>=6)}}}

{{{6<=h<=7}}}

So he can either buy 6 or 7 hot dogs. 

So the maximum number of hotdogs is 7.

Edwin</pre>