What possible values of resultant resistance one can get by combining two resistances, one of value 2 ohms and the other 6 ohm?

The equivalent resistance of a series combination of two resistances is X ohm. If the resistance are of 10 ohm and 40 ohm respectively, the value of X will be

Calculate the equivalent resistance when two resistances of 3 ohms and 6 ohms are connected in parallel.

Using Ohm's Law, calculate the resistance of combination of few resistances joined in series.

You are given resistors of 2 ohms, 4 ohms, and 6 ohms. With the help of these resistors, how can you get a resultant resistance of (i) 12 ohms, and (ii) 3 ohms? Draw diagrams to illustrate your answer.