Edexcel D1 2021 October — Question 2 6 marks

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Year2021
SessionOctober
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicLinear Programming
TypeFormulation from word problem
DifficultyModerate -0.3 This is a straightforward linear programming formulation requiring students to translate word constraints into inequalities and use the angle sum property (x+y+z=180) to eliminate z. The constraints are direct translations with minimal algebraic manipulation, making it easier than average but still requiring systematic organization of multiple conditions.
Spec7.06a LP formulation: variables, constraints, objective function

2. Chris has been asked to design a badge in the shape of a triangle XYZ subject to the following constraints.
  • Angle \(Y\) should be at least three times the size of angle \(X\)
  • Angle \(Z\) should be at least \(50 ^ { \circ }\) larger than angle \(X\)
  • Angle \(Y\) must be at most \(120 ^ { \circ }\)
Chris has been asked to maximise the sum of the angles \(X\) and \(Y\).
Let \(x\) be the size of angle \(X\) in degrees.
Let \(y\) be the size of angle \(Y\) in degrees.
Let z be the size of angle \(Z\) in degrees.
Formulate this information as a linear programming problem in \(x\) and \(y\) only. State the objective and list the constraints as simplified inequalities with integer coefficients. You are not required to solve this problem.

2. Chris has been asked to design a badge in the shape of a triangle XYZ subject to the following constraints.

\begin{itemize}
  \item Angle $Y$ should be at least three times the size of angle $X$
  \item Angle $Z$ should be at least $50 ^ { \circ }$ larger than angle $X$
  \item Angle $Y$ must be at most $120 ^ { \circ }$
\end{itemize}

Chris has been asked to maximise the sum of the angles $X$ and $Y$.\\
Let $x$ be the size of angle $X$ in degrees.\\
Let $y$ be the size of angle $Y$ in degrees.\\
Let z be the size of angle $Z$ in degrees.\\
Formulate this information as a linear programming problem in $x$ and $y$ only. State the objective and list the constraints as simplified inequalities with integer coefficients.

You are not required to solve this problem.\\

\hfill \mbox{\textit{Edexcel D1 2021 Q2 [6]}}