Find the equivalent resistances of three resistances 2 ohm, 3 ohm and 6 ohm when connected in parallel.

Find the equivalent resistances of three resistances 2 ohm, 3 ohm and 6 ohm when connected in series.

Find the equivalent resistance between A and D.

Find the equivalent resistance across A and B in the circuit.

Obtain an expression for the equivalent resistance when n identical resistors each having resistance R are connected in series.