Edexcel S1 2018 January — Question 2 8 marks

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2018
SessionJanuary
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProbability Definitions
TypeCombined event algebra
DifficultyModerate -0.8 This is a straightforward S1 question testing basic probability definitions and rules. Part (a) requires simple Venn diagram shading, (b) applies the addition rule for mutually exclusive events and definition of conditional probability (which is zero), and (c) uses the addition rule for independent events to find P(G) then applies conditional probability. All parts involve direct application of standard formulas with no problem-solving insight required, making it easier than average.
Spec2.03a Mutually exclusive and independent events2.03c Conditional probability: using diagrams/tables2.03d Calculate conditional probability: from first principles

2. (a) Shade the region representing the event \(A \cup B ^ { \prime }\) on the Venn diagram below. \includegraphics[max width=\textwidth, alt={}, center]{01259350-0119-4500-a81b-bfa1b4234559-06_355_563_306_694} The two events \(C\) and \(D\) are mutually exclusive.
Given that \(\mathrm { P } ( C ) = \frac { 1 } { 5 }\) and \(\mathrm { P } ( D ) = \frac { 3 } { 10 }\) find
(b) (i) \(\quad \mathrm { P } ( C \cup D )\) (ii) \(\mathrm { P } ( C \mid D )\) The two events \(F\) and \(G\) are independent.
Given that \(\mathrm { P } ( F ) = \frac { 1 } { 6 }\) and \(\mathrm { P } ( F \cup G ) = \frac { 3 } { 8 }\) find
(c) (i) \(\mathrm { P } ( G )\) (ii) \(\mathrm { P } \left( F \mid G ^ { \prime } \right)\)

2. (a) Shade the region representing the event $A \cup B ^ { \prime }$ on the Venn diagram below.\\
\includegraphics[max width=\textwidth, alt={}, center]{01259350-0119-4500-a81b-bfa1b4234559-06_355_563_306_694}

The two events $C$ and $D$ are mutually exclusive.\\
Given that $\mathrm { P } ( C ) = \frac { 1 } { 5 }$ and $\mathrm { P } ( D ) = \frac { 3 } { 10 }$ find\\
(b) (i) $\quad \mathrm { P } ( C \cup D )$\\
(ii) $\mathrm { P } ( C \mid D )$

The two events $F$ and $G$ are independent.\\
Given that $\mathrm { P } ( F ) = \frac { 1 } { 6 }$ and $\mathrm { P } ( F \cup G ) = \frac { 3 } { 8 }$ find\\
(c) (i) $\mathrm { P } ( G )$\\
(ii) $\mathrm { P } \left( F \mid G ^ { \prime } \right)$

\hfill \mbox{\textit{Edexcel S1 2018 Q2 [8]}}