| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Year | 2021 |
| Session | October |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Linear Programming |
| Type | Formulation from word problem |
| Difficulty | Moderate -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. |
| Spec | 7.06a 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.
\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]}}