What happens when you try to charge a mobile with multiple chargers?

[Whoaman]

Suppose i have a phone with a normal charger socket as usual AND can also charge via usb (ie 2 diff. Chargers can be connected at the same time)
now what will happen if i :-
a) use two chargers at same time.
b) use the two charger and also a bluetooth charger?
Thanks

 

[Answerguy1]

only one will work at a time