The formula for resultant resistance of three resistors connected in parallel combination is:
1
\(\rm\frac{1}{R}\) = R1 + R2 + R3
2
\(\rm\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}\)
3
R = R1 + R2 + R3
4
R = \(\rm\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}\)