Q1: The total resistance of a parallel circuit is 50 . If the total current is 120 mA, the current through the 270  resistor that makes up part of the parallel circuit is approximately

ANS:A - 22 mA

Whatever may be a count of the resistance in parallel.
That's not important here ...

here, they were given total resistance and total voltage and all the resistance is connected in parallel.
Let's make it simple..voltage across each resistance is the same (because of the parallel circuit)

Total voltage = voltage drop in anyone of the resistance part.

Total current * Total resistance = Individual current* particular resistance value,
50 *120 = x *270.
X = (50 *120)/270.
X ~ 22mA.