Given that the resistances are connected in parallel.
[tex]\begin{gathered} R_1=6\text{ ohm} \\ R_2=21\text{ ohms} \\ R_3\text{ = 27 ohms} \end{gathered}[/tex]Also, the total voltage is 7 V.
The formula to find the equivalent resistance connected in parallel is
[tex]\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}[/tex]Substituting the values, the resistance will be
[tex]\begin{gathered} \frac{1}{R}=\frac{1}{6}+\frac{1}{21}+\frac{1}{27} \\ =\frac{63+18+14}{378} \\ =\frac{95}{378} \\ R=3.97\text{ ohm} \end{gathered}[/tex]Thus, the total resistance of the circuit is 3.97 ohms.
