| Exam Board | Edexcel |
|---|---|
| Module | S1 (Statistics 1) |
| Year | 2002 |
| Session | June |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Geometric Distribution |
| Type | First success on specific trial |
| Difficulty | Easy -1.8 This is a very straightforward geometric distribution question requiring only basic probability recall. Part (a) asks for 1-1/6=5/6, and part (b) is a direct application of the formula (5/6)²(1/6) with no problem-solving or conceptual challenge beyond recognizing the geometric distribution setup. |
| Spec | 2.04a Discrete probability distributions5.02f Geometric distribution: conditions5.02g Geometric probabilities: P(X=r) = p(1-p)^(r-1) |
\begin{enumerate}
\item An unbiased die has faces numbered 1 to 6 inclusive. The die is rolled and the number that appears on the uppermost face is recorded.\\
(a) State the probability of not recording a 6 in one roll of the die.
\end{enumerate}
The die is thrown until a 6 is recorded.\\
(b) Find the probability that a 6 occurs for the first time on the third roll of the die.\\
(3)\\
\hfill \mbox{\textit{Edexcel S1 2002 Q1 [4]}}