What is the capacitance of three 100-microfarad capacitors connected in series?

For capacitors connected in series, the total equivalent capacitance is always less than the smallest individual capacitor. The formula uses the sum of reciprocals, but there is a handy shortcut for equal-value capacitors: divide the value of one capacitor by the total number of capacitors. Here, you have three capacitors that are each 100 microfarads. Dividing 100 by 3 gives exactly 33.3 microfarads. A common distractor is 300 microfarads, which you would only get if you added the values together. Remember that capacitors in series combine like resistors in parallel, not the other way around.