JAMB 2018 · UTME · Q35

If the lines $3y = 4x - 1$ and $qy = x + 3$ are parallel to each other, the value of $q$ is

Worked solution (try it first)

$3y = 4x - 1$ gives $y = \frac43x - \frac13$ , so its gradient is $\frac43$ .
$qy = x + 3$ gives $y = \frac1qx + \frac3q$ , so its gradient is $\frac1q$ .
Parallel lines have equal gradients: $\frac1q = \frac43$ , so $q = \frac34$ , option D.