If $x^{2 a}=y^{2 b}=z^{2 c} \neq 0$ and $x^2=y z$, then the value of $\frac{a b+b c+c a}{b c}$ is:
Answer & explanation
Correct answer: option 4
$x^{2 a}=y^{2 b}=z^{2 c} \neq 0$
$x^2=y z$
Then the value of $\frac{a b+b c+c a}{b c}$
Put x = y = z = a = b = c
$\frac{a b+b c+c a}{b c}$ = $\frac{1 × 1 + 1 × 1 + 1 × 1}{1 × 1}$ = 3