AQA D1 2016 June — Question 8

Exam BoardAQA
ModuleD1 (Decision Mathematics 1)
Year2016
SessionJune
TopicLinear Programming

8 Nerys runs a cake shop. In November and December she sells Christmas hampers. She makes up the hampers herself, in two sizes: Luxury and Special. Each day, Nerys prepares \(x\) Luxury hampers and \(y\) Special hampers.
It takes Nerys 10 minutes to prepare a Luxury hamper and 15 minutes to prepare a Special hamper. She has 6 hours available, each day, for preparing hampers. From past experience, Nerys knows that each day:
  • she will need to prepare at least 5 hampers of each size
  • she will prepare at most a total of 32 hampers
  • she will prepare at least twice as many Luxury hampers as Special hampers.
Each Luxury hamper that Nerys prepares makes her a profit of \(\pounds 15\); each Special hamper makes a profit of \(\pounds 20\). Nerys wishes to maximise her daily profit, \(\pounds P\).
  1. Show that \(x\) and \(y\) must satisfy the inequality \(2 x + 3 y \leqslant 72\).
  2. In addition to \(x \geqslant 5\) and \(y \geqslant 5\), write down two more inequalities that model the constraints above.
  3. On the grid opposite draw a suitable diagram to enable this problem to be solved graphically. Indicate a feasible region and the direction of an objective line.
    1. Use your diagram to find the number of each type of hamper that Nerys should prepare each day to achieve a maximum profit.
    2. Calculate this profit.
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