Four 20-ohm resistors are connected in series and the combination is connected to a 20 V emf device. The current in any one of the resistors is:

A) .25 A
B) 1.0 A
c) 4.0 A
D) 5.0 A
E) 100 A

My answer: A
R= 20 + 20 + 20 + 20 =80
V= IR
20/80=I
I=.25

A battery with an emf of 24 V is connected to a 6 ohm resistor. As a result, current of 3 A exists in the resistor. The terminal potential diference of the battery is:
A)0
B) 6 V
c) 12 V
D) 18 V
E) 24 V

My answer is D 18V. It wants to know the terminal resistance so V=IR or
V=6 *3= 18 V

Thank you

correct