Question
Enviro Build is a construction company that recently purchased land. It has permission to build either small houses or large houses but not both types of house. The maximum number of small houses that can be built is 10 . The maximum number of large houses that can be built is five.
The cost of building the houses is calculated using a model with the following three variables:
House_Type: The type of house (small or large).
House_Num: The number of houses to be built.
Profit: The total sales revenue minus the land costs, labour costs and material costs.
The decision whether to build small houses or large houses is a purely financial one and is based on the following information:
- A single payment of $\$ 500000$ for the land, regardless of whether 10 small houses or five large houses are to be built.
- The revenue from each house sale will be $\$ 220000$ for a small house and $\$ 400000$ for a large house.
- The labour costs will be $\$ 2500$ per day, regardless of the type of house built.
- It will take 17 days to build each small house and 23 days to build each large house.
Houses are built sequentially so that they can be sold as soon as they are completed.
- The material costs will be $\$ 100000$ for each small house and $\$ 190000$ for each large house.
a. Identify the data types for the House_Type, House_Num and Profit variables. [3]
b. Construct a spreadsheet model that shows the total profit for the chosen type of house. The user must input the House_TYpe and House_Num to [6]
calculate the total profit.
c. Outline two validation tests that should be included in the test plan for this spreadsheet model.[4]
d. To finance this project, EnviroBuild took out a bank loan of $\$ 400000$ and will be required to pay interest on this loan. The project starts on 1 [5]
January 2021.
The following steps are used to calculate the total profit:
- Read the Profit variable and the No_of_Days variable from the spreadsheet model in (b).
- Calculate the number of months that the project will take.
- There are no partial months.
- For example, if a project finished on 1 July 2021 , the loan interest rates will include July: the project will last for 7 months.
- The rate of interest on the bank loan of $\$ 400000$ is $1 \%$ per month.
- The land tax is $\$ 500$ per month.
Construct the pseudocode that will calculate the profit after these additional costs have been considered. You can introduce any new variables, if necessary.
▶️Answer/Explanation
Ans:
a. )
House_Type: char/string/Boolean;
House_Num: integer;
Profit: fixed-point decimal/currency/float/double;
b.)
Award [1] for including HOUSE_TYPE and HOUSE_NUM as input
Award [1] for calculating total revenue;
Award [1] for calculating the number of days for each project
Award [1] for calculating the labour costs
Award [1] for calculating material costs
Award [1] for calculating the profit
REVENuE: Award [1] for Sales_price * House_Num based on the If statement
NUM_DAYS: Award [1] for the correct number of days * house_num.
LABOUR_COSTS: Award [1] for NUM_DAYS * 2500
MATERIAL_COSTS: Award [1] for checking the HOUSE_TYPE and then multiplying HOUSE_NUM by the correct material cost.
PROFIT: Award [1] for deducting all of the costs from the revenue.
Example answer:
Alternative solution:
Note: accept cell references such as $B 3$ instead of variables
c. )
Award [2 max] for each variable tested.
Award [1] for the type of test and [1] for example test data.
Type test for HOUSE_TYPE
Normal: s or I / small or large; Abnormal: $m$ / medium.
If Boolean has been used Normal: True or False; Abnormal: “small”
Range test for NUM_HOUSES
Normal HOUSE_NUM $=5 /$ Abnormal HOUSE_NUM $=12 /$ Extreme HOUSE_NUM $=6$ or HOUSE_NUM $=10$
Accept any testing that relates to:
- normal data // Note: an example will get this mark
- extreme data
- abnormal data.
d. )
Award [1] for reading the profit, number of days from csv file / cell range.
Award [1] for adding the number of days to the date.
Award [1] for extracting the month from the date.
Award [1] for calculating interest and rates.
Award [1] for deducting the costs from the profit and displaying result.
Example pseudocode:
import FILE.CSV As SS
read PROFIT, NUM_DAYS from SS
END_DATE = #01/01/2021 + NUM_DAYS
NUM_MONTHS = MONTH(END_DATE)
COSTS = (NUM_MONTHS * 500) + (NUM_MONTHS * (400000 * .01))
output (PROFIT – COSTS)
Alternative pseudocode:
input Profit, NumDays from spreadsheet
endDate = date(dateval(“1/1/21”) + NumDays)
monthsTaken = month(endDate)
interest = 400000 * 0.01 * monthsTaken
output “Net profit = $”, (Profit – interest)
Question
Many health agencies are using simulations in an attempt to understand how their resources could be used in the future. With many countries
experiencing aging populations, health agencies have worked with computer scientists to develop simulations that will enable them to manage their resources more effectively.
One of the key features of these simulations is the development of “what-if” models.
The following variables can be considered as part of a model to be used to simulate the management of an aging population:
- quality of health education
- lifestyle choices such as smoking
- residential region.
a. Describe the main features of a “what-if” model.[4]
b. Identify three other variables that could be included in this model.[3]
c. Explain the ethical issues that may arise from the collection of information for this model.[5]
d. Explain why the model would be converted to a simulation.[3]
▶️Answer/Explanation
Ans:
a. )
Data is entered into a rule-based environment;
The rules may be kept the same and the nature of the data input may be varied;
Or the data that is input may remain the same and the rules may be varied;
Which allows for a range of possible scenarios to be investigated;
b.)
Life expectancy;
Gender;
Availability of life-extending treatments;
Genetic information;
Allow other appropriate answers.
c.)
Example answer:
One ethical issue is invasion of privacy;
to get the best quality model;
sensitive personal data will need to be collected;
trade-off between the benefits of this model and level of intrusion into people’s lives;
especially if the data is being shared with third parties;
d. )
Simulation may be used to handle uncertainty and provide ranges of expected outputs; e.g. repeatedly inputting data drawn from random samples of plausible input values;
To look at the predicted spread of outcomes over time (consider the use of simulation in the analysis of queues);
A simulation is considered to be a representation of a model over time;
This means that the simulation can be used over a longer period of the development life cycle;
It can be used to assist with stages such as the implementation stage;