Explanation :
It is given that,
In the given figure all the three resistors are in series.
Current flowing in the circuit, [tex]I=3\ A[/tex]
Voltage, [tex]V=30\ V[/tex]
We know that in series circuit the current flowing in all resistors is same.
Using Ohm's law, we get:
[tex]V=IR[/tex]
[tex]30\ V=3\ A(2\ \Omega+3\ \Omega+R_3)[/tex]
[tex]R_3=5\ \Omega[/tex]
Hence, this is the required solution.
