Find the highest common factor of  \(12\), \(15\)  and  \(24\).

Joyce borrows \$5000 to buy a used car. The bank charges a 9.8% per annum flat rate of interest over 30 months. How much is each equal monthly repayment?

Solve $\dfrac{{x + \sqrt x }}{{x – \sqrt x }} = 2$.

Find \(A\), \(B\), \(C\)  and  \(D\)  if   \(\left( { – x + 3} \right)\left( {x + 2} \right)\left( {2x + 3} \right) = A{x^3} + B{x^2} + Cx + D\).

Find the positive value of \(b \), if the vertex of \(y = {x^2} – 2bx + 3\) is \(\left( {b, – 13} \right)\).

Find  \(k\)  given  \(\vec a = \left( {\begin{array}{*{20}{c}}
2\\
k
\end{array}} \right)\)  and  \(\vec b = \left( {\begin{array}{*{20}{c}}
5\\
1
\end{array}} \right)\)  are perpendicular.

Find the interior angle of a 30-sided regular polygon.

Find the largest angle in the triangle, correcting to the nearest degree.

The Venn diagram below shows the number of students in group \(A\), \(B\) or \(C\).   Find the number of students who are in at least one of groups.

Describe the strength of the linear relationship with correlation coefficient \(r = – 1\).