how do people attain so much money in gta online?

when i would play gta online with my friends on xbox live, they have these flashy cars huge garages and nice apartments, all i have is a small apartment with a garage that can only hold two cars which took me forever to get. so how do people get a whole bunch of money in such little amount of time without buying in-game cash? how much money do the armored trucks hold?

missions and races. You should do Rooftop rumble a lot, and you get lots of money

@The_Last_Ride: i know but those pay so little ,(2,000-11,000) ,rarely i would get paid 11,000 if i work with 3 other guys and kill everyone.

They hack or use a mod hack or get someone who is hacking to give them the cash.

Or the last option which i find a bit meh, they actually played the game so much that they earned the cash.

Game exploits and hackers

true, but that's the fastest one at least when i played. They might have cut the money. I know they made the mission longer a while back. But you still get lots of money

Probably paying real money for ingame money.

@The_Last_Ride: how much money did they pay when you first got online?

damn i think it was around 20k, not sure though, but it was a lot and the mission was way shorter