how do wheels and tires work THO

[uh-oh]

aight my bronco right. when i bought it, it didnt have the spare wheel, or that wheel holder thing most broncos have on the back

since im moving soon farther from my work, and these tires are close to a year old now (still good tread tho they're solid) i figure i should get around to getting a spare. i honestly just kept forgetting about it lol

but here is the thing, the tires i got on it now i'm pretty sure are 31 by 10 and a half by 15. which is 31 tall, ten and a half wide, and on a 15 inch rim right?

ok so i was just browsing around the net since i just remembered, and i'm finding bronco rims that look the same as mine, the OEM shits, but they're all 7.5 wide not 10.5. granted i couldve read the tire wrong maybe but i doubt it.

so basically would a 10.5 tire even fit that? im guessing no right?

this weekend, should i go to tire shops, or junkyard/pull a part places

i'd like to spend the least possible but i'd also like to have a rim that matches, but in reality it doesn't matter its just gonna be my spare if i blow one out, and im going to keep it in the truck next to my sub since i don't have the tire bar thing anyways so it ain't like its on display

but word any of you dudes know about this shit