JAMB Mathematics 2012 Paper

Concept:Set intersection means picking only the elements that are present in both sets.First list each set, then find the common members.Explanation:Prime factors of 30 are $P = \{2,3,5\}$.The factors of 18 are $1,2,3,6,9,18$.Since $Q$ contains only factors of 18 that are less than 10, we get $Q = \{1,2,3,6,9\}$.Notice that $1$ is in $Q$, but it is not a prime factor of 30, so it will not affect the intersection.Now compare the two sets: the numbers common to both $P$ and $Q$ are $2$ and $3$.Therefore, $P \cap Q = \{2,3\}$.This matches option B.Answer:$\{2,3\}$ (Option B).