Question 125658
I would just do guess and check.  Every time he buys another 2 $.22 stamps, he buys 1 more $.14 stamp.  So he spends .22+.22+.14=$.58 at a time.  This might need to be changed when we get closer to the answer, but for now this works.
So let's start with 10 of these bunches- that's $5.80.  Slightly more than half.  Try 18- that's $10.44- a bit too much!  Try 17- 9.86- so it's around 17 bunches.  Now, we had 2 $.22 stamps in each, so that's about 34.  So if it was 34 $.22, it's 17 $.14 stamps.  Does that work?  (34*.22)+(17*.14)=7.48+2.38=9.86- so that part worked.  If he buys one more of anything, he goes over.  So the answer must be 34.