Sleepy Joe needs to
get some rest. Can you set the level of the current flowing through the
resistors to his light so that the light will go off and he can get some
sleep?
To do this, the current in all four branches of
the circuit must be equal. The bottom two branches are set to one ohm. The
upper left branch has two serial resistors, and the upper right branch has
two parallel resistors. Values for serial resistors add together for a total
current. The total for resistors in parallel is found by multiplying them
together, and dividing that result by the sum of adding them together. When
the values of the two upper branches are equal, the light will go off.
Give up? Here's the puzzle solution.