If there is only ONE driver unit (the one labelled 50W) then each LED will have a power of 120/50 or approximately 0.5W (to be on the safe side it is recommended that you use somewhat LESS LED wattage than the driver can provide so, more accurately speaking, the LEDs should be nearer 0.3W or 0.4W to give a total wattage of 120 x 0.3 = 36W, or 120 x 0.4 = 48W)
Whatever - all you can fit is a total of 50W assuming that 50W driver is the ONLY ONE.
If there are 10 or 12 LEDs PER DRIVER (assuming there's more than one.....) then each LED will be rated at around 4 or 5 watts.
They LOOK like 1W LEDs but looks can be deceiving.
You should gather from the confusion that abounds in this thread that telling us EVERYTHING about your setup is the only way to get the right answer.
So - how many drivers?