Question

What is the total resistance of three 6-ohm resistors hooked in parallel

Answer 1

The equivalent resistance of n resistors in parallel is given by
$\frac{1}{R_{eq}}= \frac{1}{R_1}+ \frac{1}{R_2}+...+ \frac{1}{R_n}$

In this case, we have three resistors of $6 \Omega$ each, so their equivalent resistance when they are connected in parallel is
$\frac{1}{R_{eq}}= \frac{1}{6 \Omega}+ \frac{1}{6 \Omega}+ \frac{1}{6 \Omega}= \frac{3}{6 \Omega}$
Which gives
$R_{eq}= \frac{6 \Omega}{3}=2 \Omega$