Calculate the equivalent resistance of the combination of three resistors of 2 ohm ,3ohm,and 6ohm joined in parallel?

The total resistance is 1ohm

When resistors are arranged in series the total resistance can be calculated as the sum of all the resistors in the series. When the resistors are arranged in parallel the total resistances is calculated by summing up the reciprocals of all the values of resistance and then finding the reciprocal to the answer.