I’m trying to translate the following sentence (I’ve marked it with red arrows) http://imgur.com/LDcSUJ0. Here’s what i got:
“And also many treasures and rich [adj] exist in the temple there, and in it many gifts exist of many people.”
Your translation is essentially correct, but where English would say “many rich treasuries,” Greek says θησαυροι πολλοι και πλουσιοι. πλουσιοι is an adjective modifying θησαυροι.
In both cases, instead of “exist”, “there is/are” would be better.
θησαυρος usually means a “treasury” – a storage place for treasure, not the treasures themselves.
“I can’t see how an adjective and a noun can be equal.” In Greek, as in English to a lesser extent, an adjective with the article can be used as a noun: for examplbe, οι πλουσιοι would mean “the rich” or “rich people”. That’s not what’s going on here, however. As I noted above, πλουσιοι is simply an adjective modifying θησαυροι, but Greek, unlike English, requires the two coordinate adjectives πολλοι and πλουσιοι to be conjoined by και. You should note this idiomatic Greek usage–it comes up frequently.
Hope this helps.