Calculate the resultant resistance when three resistances of $3\Omega$ are connected in parallel?

Suppose $R$ is the total resistance of parallel combination then it is given by

$\dfrac {1}{R} = \dfrac {1}{R_{1}} + \dfrac {1}{R_{2}} + \dfrac {1}{R_{3}}$

Given - $R_{1} = R_{2} = R_{3} = 3\Omega$

or $\dfrac {1}{R} = \dfrac {1}{3} + \dfrac {1}{3} + \dfrac {1}{3} = 1$

Thus $R = 1\ Ohm$.