(a)[1]
Because $p$ is directly proportional to $q$, work out the value of $r$.
(b)[1]
Complete the sentence below to describe the relationship between $x$ and $y$. $y$ is inversely proportional to __________.
(c)[1]
$M$ is directly proportional to $L^3$. By how many times does $M$ increase when $L$ is multiplied by $2$?