A battery with EMF = 20V has an internal resistance r = 1.6 Ohm. Two resistors with resistances R1 = 4 ohms and R2

A battery with EMF = 20V has an internal resistance r = 1.6 Ohm. Two resistors with resistances R1 = 4 ohms and R2 = 6 ohms, connected in parallel, are used as a load. What is the current I flowing through the battery?

With parallel connection of resistances, the total resistance is:
R = R1 * R2 / (R1 + R2) = 24/10 = 2.4 ohms.
From Ohm’s law for a common circuit:
I = E / (R + r),
Where
E = 20V – battery EMF,
R = 2.4 Ohm – total external resistance of the circuit,
and r = 1.6 Ohm is the internal resistance of the battery.
I = 20V / (1.6 Ohm + 2.4 Ohm) = 20V / 4 Ohm = 5A.