dev.physicslab. org/asp/nyregents/2003/January/part3.asp

Question

Why is the answer to #47 2 amperes? How do I get that?

Answer 1

current entering node=current leaving node
A+3+2=4+1+2

" These sum of the currents entering a node is zero" ie, A=3+2-4-1-2=0

Answer 2

Thank you!