42/24 isn't going to cut it in hills for any but seriously strong riders. Buy yourself a wider range freewheel for starters, but even that may not be enough.

BTW- there's never a problem with a chain cut to Maximum length. Loop the 42/24 combination through the derailleur and take up slack until the idler cage moves off the dead stop. That's the longest chain length that will work in all gears, and will leave room for a larger freewheel later.