Originally Posted by
creativepart
On the hybrid I use the granny on at least 3 of those hills. I've tried making it with my 36/26 and am unable. I generally use my 26/18 or so.
You should have gotten the triple.
Unfortunately it's not cheap to convert a bike from double to triple because you need new shifters in addition to the new crank and derailleurs, and shifters are the most expensive part.
If you are local to the bike store you bought it from, and have not ridden the bike yet, I'd take it back and ask nicely what it would take to get a triple on it. If they can reuse the existing components because they are unused, it might be cheaper.
If it's too expensive then you can settle for a compact crank and a wide-range rear cassette, but I think that for your condition and use a triple would suit you better. A 9sp Shimano mtb derailleur will shift a wide range 10sp cassette with your 10sp shifters.