Please help! What is the equivalent resistance of the combination?
In order to find equivalent resistance you need to know how to add up resistors. The vertical resistor isn’t connected to anything and thus draws no current. Resistors in parallel add up like this: 1/R+1/R = 1/Rt where Rt is your total resistance. Resistors in series add up directly. So for your problem you have 1/R + 1/R which equals 2/R which is equal to 1/Rt solving for Rt you have to take the reciprocal which is R/2. This converts the parallel resistors to an equivalent resistor in series with the other 2.
