What is the total resistance of a 10-, a 20-, and a 50-ohm resistor connected in parallel?

To find the total resistance of resistors in parallel, use the reciprocal formula: 1/Rt = 1/R1 + 1/R2 + 1/R3. For these resistors, the equation is 1/Rt = 1/10 + 1/20 + 1/50. Converting the fractions to decimals, this is 0.10 + 0.05 + 0.02 = 0.17. To find the final answer, you must take the reciprocal of 0.17 (1 / 0.17), which equals approximately 5.88 ohms, rounding to 5.9 ohms. A helpful rule of thumb to check your math is that the total resistance of parallel resistors will always be less than the value of the smallest individual resistor in the group (in this case, less than 10 ohms).