ADVANCED Numerical Tests , livre ebook

Advanced
Numerical Tests




Thanks for your interest in the ultimate guide to passing numerical psychometric tests and congratulations on taking the next steps towards gaining that dream job.
The structure of this book takes you upon a journey which gradually improves your confidence in answering numerical psychometric test questions. It contains 51 realistic questions designed to imitate the real tests and 53 detailed answers with full explanations to match in order to improve your understanding of what is expected of you and how to answer the questions quickly and correctly every time.
I urge you not to sit the mock exam until you have gone through every example in the book as this will most likely damage your confidence before you have even started to build it up!. Remember that in order to improve, practice and persistence is the key.
Before we begin, I highly recommend investing in a scientific calculator if you have not done so already. Doing this will save you a lot of time during the exams and many of the time saving tips I have provided you throughout the book contain information on how to save time in the exam using a scientific calculator.
Where you see a number highlighted in grey, for example £ 4022.74, it is there because that particular number will shortly be used within an equation which follows. The idea is that if you see a number highlighted in grey within an equation, you will know where the number came from. I know exactly what it’s like trying to find where a number which appears in an equation came from and I hope this simplifies the process for you.
I will be with you every step of the way during this book and I wish you every success in gaining the job of your dreams.
Let the journey to success begin right here and right now.
David Isaacs
AUTHOR, 2011




Q1. Data Interpretation
Question 1a)
The image below shows the cumulative number of births in various locations across the UK over a period of 4 months.

“For the month of September, how many births took place in Maidstone?” a) 9 b) 1,200 c) 3,000 d) 200 e) 250
Solution to question 1a)

Note: The graph data is cumulative. What this means is that the data is increasing by successive addition for every month, starting with the month of September.
The following is a good explanation of how cumulative graphs, such as the one above function. Assume you get an income paid into your bank every week. On the first week you get paid, you spend nothing from your earnings and then get paid again the second week, but an unspecified amount. Your income for the second week could be higher or lower than your earnings on the first week. A cumulative data graph would not tell you directly how much income you have made for the second week, but what it would tell you directly is how much income you have had in total over the two weeks.
Referring back to the question, sadly, this means that it is not simply a matter of reading straight off the graph to see how many births took place in September, which I am sure every reader would no doubt prefer it to be!. The procedure to get the correct answer is outlined below:
For the month of September, in Maidstone, I need to look at the two points located above 31 st August and 30 th September and then find the difference between them:
Follow the 30 th September upwards from the x-axis* until it hits the Maidstone curve, the data point sits on the number 4 in the y-axis*. Do the same for the 31 st August. Following it upwards until it hits the Maidstone curve reveals that the data point lies on the number 2 in the y-axis. Both points are circled in the diagram below for clarity.
*The x-axis is the horizontal component of any graph and the y-axis is the vertical component of any graph.

To find the difference, subtract both points from each other: 4 - 2 = 2
The next thing I need to consider is that the title of the graph tells me that all numbers used in the graph are shortened by two zeros [Cumulative Births (00s)]. So, for the difference I just calculated between the two points above 30 th September and 31 st August, the number 2 becomes 200.
This is the answer to part a), 200




Question 1b)

“How many births, in total, took place in Ringwood during the months of September, October and November?” a) 300 b) 3 c) 250 d) 900 e) 750
Solution to question 1b)
For this question it is important you understand that the graph is cumulative, the definition of which is given in the solution to part a).
Looking at the Ringwood curve on the graph, I need to find how many births took place each month, starting from September and ending in November, as the question requests.
To do this, I follow the same procedure shown in part a), but this time there are an extra 2 months to carry it out for:
Birth’s at Ringwood in September:

To calculate the birth’s at Ringwood in September, subtract the two points circled in the above graph:
8 - 6 = 2
The title of the graph tells me that the numbers in the data are shortened by two zeros so I now add two zeros to this, which brings the number of births at Ringwood in September to 200.
Birth’s at Ringwood in October:
The same procedure as shown above is followed; the only difference is that the numbers being subtracted are taken from the October value on the graph for Ringwood, circled below:

Calculation for number of Births at Ringwood in October:
9 - 8 = 1
Adding the two zeros to the end of this gives 100 births at Ringwood in October.
Birth’s at Ringwood in November:
Following the same procedures shown above, and subtracting the two circled points below leads to a figure of zero:
9 - 9 = 0

This means that at Ringwood, in the month of November, there were no births.
Births at Ringwood in September, October and November:
To calculate the total number of births, simply add each month’s births, calculated above:
There were 200 births in September, 100 births in October and 0 births in November, the total is therefore:
200 +100 + 0 = 300
The answer to question 1 b) is therefore 300




Question 1c)

“Assuming that the birth trend for Coventry seen in the month of December continues into January, how many births will take place in total during the months of November, December and January for Coventry?” a) 30 b) 600 c) 6 d) 300 e) 150
Solution to question 1c)
This question is asking me to assume ‘that the birth trend for Coventry seen in the month of December continues during the month of January.’ If this were to be drawn on the cumulative graph it would look like the following graph:

It can now be seen from the above graph that if the birth trend for Coventry seen in December continues in the month of January, there would be 300 births in January, the same number of births seen in the month of December.
However, during the actual test, it would not be wise to draw out a graph due to time constraints. I will therefore now outline the procedure and thinking you should follow during the actual timed test below:
During the month of December for Coventry, there were 300 births. This was calculated by subtracting the two circled points shown in the graph below:

8 - 5 = 3
The next step is to add two zero’s to the end of the 3 as the title of the graph states that every number is shortened by two zeros, to give 300. Because the question states that it should be assumed the December birth trend for Coventry is continued in January, this can only mean that there were 300 births in January also, bringing the Coventry line to the 11 mark on the y-axis at the end of the month of January as shown in the graphs above.
The next step is to calculate the number of births for Coventry during the month of November.
Fortunately, there is a flat line representing the number of births in November for Coventry, which means that there were no births during this month.
Don’t just take my word for it, see for yourself. The calculation would be to subtract the two points circled on the graph below:

The calculation is: 5 - 5 = 0 births
The next and final step to take is to add the number of births that took place in the months of November, December and January for Coventry:
0 + 300 + 300 = 600 births
Therefore, the answer to part c) is 600 births took place during the months of November, December and January for Coventry.




Question 1d)

“If the trend in the number of births seen for Alfreton in the month of November continues into the month of December, what reduction in births will Alfreton have had for the month of December compared to what the data currently shows?” a) 300 b) 1,200 c) 100 d) 1,500 e) 290
Solution to question 1d)
This question requires an assumption that the trend in the number of births seen for Alfreton in the month of November continues into the month of December. If this were to be the case, the difference between the original graph and the graph that includes this assumption would look like:

ORIGINAL GRAPH (Note the 31st December point for Alfreton)

GRAPH INCLUDING ASSUMPTION (Note the change on the 31st December point for Alfreton, it has reduced from hitting the y-axis at 15 to hitting it at 14)
The question is asking for the reduction in the number of births when comparing the two graphs. This can be solved in three easy steps: 1) I firstly need to know the original number of births in the month of December for Alfreton. This can be calculated using the original graph.
The procedure