| Exam Board | WJEC |
|---|---|
| Module | Unit 2 (Unit 2) |
| Session | Specimen |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Probability Definitions |
| Type | Combined event algebra |
| Difficulty | Moderate -0.8 This is a straightforward probability question testing basic definitions (mutually exclusive, independent, subset) with direct formula application. Part (a) uses P(A∪B)=P(A)+P(B), part (b) uses P(A∪B)=P(A)+P(B)-P(A)P(B), and part (c) immediately gives P(A∪B)=P(B). No problem-solving or insight required—pure recall and substitution into standard formulas, making it easier than average. |
| Spec | 2.03a Mutually exclusive and independent events |
The events $A, B$ are such that $P(A) = 0.2, P(B) = 0.3$. Determine the value of $P(A \cup B)$ when
\begin{enumerate}[label=(\alph*)]
\item $A,B$ are mutually exclusive, [2]
\item $A,B$ are independent, [3]
\item $A \subset B$. [1]
\end{enumerate}
\hfill \mbox{\textit{WJEC Unit 2 Q1 [6]}}