OCR D1 2009 January — Question 1 6 marks

Exam BoardOCR
ModuleD1 (Decision Mathematics 1)
Year2009
SessionJanuary
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFixed Point Iteration
TypeApply iteration to find root (pure fixed point)
DifficultyEasy -1.8 This is a straightforward flowchart tracing exercise requiring only careful arithmetic and bookkeeping. No mathematical insight or problem-solving is needed—students simply follow the algorithm step-by-step and record values. This is significantly easier than typical A-level questions which require applying mathematical techniques or reasoning.
Spec7.03a Algorithm definition: input, output, deterministic, finite7.03c Working with algorithms: trace, interpret, adapt

1 The flow chart shows an algorithm for which the input is a three-digit positive integer. \includegraphics[max width=\textwidth, alt={}, center]{43fe5fd5-4b98-4c3a-90ca-a1bd5cf065fe-2_1294_1493_356_328}
  1. Trace through the algorithm using the input \(A = 614\) to show that the output is 297 . Write down the values of \(A , B , C\) and \(D\) in each pass through the algorithm.
  2. What is the output when \(A = 616\) ?
  3. Explain why the counter \(C\) is needed.

1 The flow chart shows an algorithm for which the input is a three-digit positive integer.\\
\includegraphics[max width=\textwidth, alt={}, center]{43fe5fd5-4b98-4c3a-90ca-a1bd5cf065fe-2_1294_1493_356_328}\\
(i) Trace through the algorithm using the input $A = 614$ to show that the output is 297 . Write down the values of $A , B , C$ and $D$ in each pass through the algorithm.\\
(ii) What is the output when $A = 616$ ?\\
(iii) Explain why the counter $C$ is needed.

\hfill \mbox{\textit{OCR D1 2009 Q1 [6]}}