PAST QUESTIONS 1990


Section A

Time yourself to improve on your speed. You are to use not more than 60 minutes for this section.

Click on the link below when you are ready.





Highest score: \(\mathbf{\frac{35}{40}}\)

Malvin Agyemang






Section B

Try the questions first, using not more than 15 minutes for each question, and watch the accompanying videos to see how the questions are solved.






Question 1


  1. List the members of each of the sets

  2. \( B=\){Whole numbers from 20 to 30} and
    \( D=\){factors of 63}
    List the members of:
    \((i)\) \(B \cap D\)
    \((ii)\) \(B \cup D\)

    Solution

    \(B=\) {Whole numbers from 20 to 30}

    \(\Rightarrow B =\) {20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30}

    \(D=\) {factors of 63}

    \(\Rightarrow D =\) {1, 3, 7, 9, 21, 63}


    \((i)\) \(B \cap D =\) {21}

    \((ii)\) \(B \cup D =\) {1, 3, 7, 9, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30}






    Watch the video below for a walk-through of the solution.





  3. In a class of 60 students, 46 passed Mathematics and 42 passed English Language. Every student passed at least one of the two subjects.

  4. \((i)\) Illustrate the information on a Venn Diagram.

    \((ii)\) How many students passed in both subjects?

    Let \(n\) represent the number of students who passed in both subjects.


    Solution

    Let \(\mathbb{U} \Rightarrow\) the total students in the class.

    Let \(M \Rightarrow\) students who passed Mathematics.

    Let \(E \Rightarrow\) students who passed English.

    Let \(n \Rightarrow\) number of students who passed in both subjects.

    \(n(\mathbb{U}) = 60\)

    \(n(M) = 46\)

    \(n(E) = 42\)


    \((i)\)

    Venn diagram

    \((ii)\) \(46 -n + n + 42 - n = 60\)

    \(46 + 42 - n = 60\)

    \(88 - n = 60\)

    \(88 - 60 = n\)

    \(\Rightarrow n = 28\)

    \(\therefore\) 28 students passed in both subjects.













Question 2


  1. Factorise completely:

  2. \(3a^2 + 2ab - 12ac - 8bc\)

    Solution

    \(3a^2 + 2ab - 12ac - 8bc\)

    \(a(3a + 2b) - 4c(3a + 2b)\)

    \(\Rightarrow (3a + 2b)(a - 4c)\)






    Watch the video below for a walk-through of the solution.





  3. Solve \(\frac{x}{4} + \frac{3}{5} = \frac{3x}{2} - 2\)

  4. Solution

    \(\frac{x}{4} + \frac{3}{5} = \frac{3x}{2} - 2\)

    Multiplying through by LCM of 20:

    \(\Rightarrow \frac{x}{4}(20) +\) \(\frac{3}{5}(20) =\) \(\frac{3x}{2}(20) - 2(20)\)

    \(\Rightarrow 5x + 3(4) = 3x(10) - 40\)

    \(\Rightarrow 5x + 12 = 30x - 40\)

    Grouping like terms:

    \(\Rightarrow 12 + 40 = 30x - 5x\)

    \(\Rightarrow 52 = 25x\)

    \(\Rightarrow \frac{52}{25} = \frac{25x}{25}\)

    \(\Rightarrow x = \frac{52}{25}\)

    \(\Rightarrow x = 2\frac{2}{25}\)

    \(\therefore x\) is \(2\frac{2}{25}\)






    Watch the video below for a walk-through of the solution.





  5. Find the solution set of \(x + 3 > 19 - 3x\), where \(x\) is a real number.
    Illustrate your answer on the number line.

  6. Solution

    \(x + 3 > 19 - 3x\)

    Grouping like-terms:

    \(\Rightarrow x + 3x > 19 - 3\)

    \(\Rightarrow 4x > 16\)

    \(\Rightarrow \frac{4x}{4} > \frac{16}{4}\)

    \(\Rightarrow x > 4\)

    \(\therefore\) the solution set is {\(x:x > 4, x \in\) real numbers}


    number line











Question 3


  1. Using a ruler and a pair of compasses only:
  2. \((i)\) Construct a triangle \(PQR\) such that \(|PQ| = 6cm\), \(|QR| = 4cm\) and \(\angle PQR=90°\).

    \((ii)\) Construct perpendicular bisectors (mediatos) of \(PQ\) and \(QR\). Name the intersection of the mediators \(O\)

    \((iii)\) Draw a circle with \(O\) as center and \(OQ\) as radius.


  3. Measure
  4. \((i)\) \(\lvert PR \rvert \)

    \((ii)\) \(\angle QPR\)

Solution

Question 3\((a)\)

construction

Question 3\((b)\)

\((i)\) From the diagram:

\(\hspace{0.5cm} \lvert PR \rvert = 7.2\) cm

\((ii)\) From the diagram:

\(\hspace{0.5cm} \angle QPR = 34^\circ\)













Question 4


The following is the result of a survey conducted in a class of a Junior Secondary School to find the favourite soft drink of each pupil in the class.

table for question 4
  1. Draw a bar chart showing this information, using a scale of 2cm to 1 unit on the vertical axis.
  2. How many pupils are in the class?
  3. What percentage of pupils in the class prefer Club Cola?


Solution

Question 4\((a)\)

Question 4\((b)\)

Total students in the class

\(\Rightarrow \) 6 + 5 + 8 + 3 + 5 + 4 + 6 + 3

\(\Rightarrow \) 40

\(\therefore \) there are 40 students in the class.


Question 4\((c)\)

Total students in the class \( = 40\)

Number of students who prefer Club Cola \( = 6\)

Percentage of students who prefer Club Cola

\(\Rightarrow \dfrac{Number \ prefering \ Club \ Cola}{Total \ Students} \times 100\% \)

\(\Rightarrow \dfrac{6}{40} \times 100\% \)

\(\Rightarrow \dfrac{2 \times 3}{2 \times 20} \times 100\% \)

\(\Rightarrow \dfrac{3}{20} \times 100\% \)

\(\Rightarrow 3 \times 5\% \)

\(\Rightarrow 15\% \)

\(\therefore \underline{15\% \ of \ students \ prefer \ Club \ Cola.}\)










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