Edexcel D1 — Question 2

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
TopicCombinations & Selection

2. This question should be answered on the sheet provided. A builder is going to put up houses on a plot of land of area \(12000 \mathrm {~m} ^ { 2 }\).
There are 5 designs to choose from and no more than one of each design can be built.
DesignKendalMilvertonArlingtonElfordGrosvenor
Plot area ('000 \(\mathrm { m } ^ { 2 }\) )3113510
Value ( \(\pounds ^ { \prime } 000 \mathrm {~s}\) )1001904080120
The builder needs to work out which houses he should build in order to maximise the total value of the site. He does this using a tree diagram and each "branch" on the tree is terminated when the total area of land on that branch exceeds \(12000 \mathrm {~m} ^ { 2 }\).
    1. Complete the tree diagram so that each branch is terminated or all choices have been considered.
    2. Hence, determine which designs the builder should use and the total value that the site will have when completed.
  1. Explain how this method could be altered if more than one of each design is allowed.