1019 past contests
Topic 23 · Solving $\dfrac{x}{x-2}\lt0$ by critical points
Topic 33 · Riddles: the regular polygon, circle, square and triangles
Topic 19 · Factorised equation of the parabola with $x$-intercepts $1$, $3$ and $y$-intercept $9$
Topic 8 · Solving $(x-3)^{x-3}=1$
Topic 45 · Reflection of the line $5x+3y=15$ in the line $y=x$
Topic 4 · Average radius of three balls of $3$ mm (true/false)
Topic 11 · Determinant test: does $t(x,y)\to(x-y,\ x+y)$ have an inverse? (true/false)
Topic 9 · Expressing $193$, $145$ and $157$ as sums of two squares of natural numbers
Topic 27 · Least perimeter of a rectangle of fixed area $96\ \text{cm}^2$: $p=2x+\dfrac{192}{x}$
Topic 4 · Riddle: mean deviation as a measure of variation
Topic 8 · Metric (si) prefixes as powers of ten (true/false)
Topic 10 · Probability that two fair dice give a total of $8$ with both scores even or both odd
Topic 7 · Closure of division on integers, non-zero rationals and irrationals (true/false)
Topic 19 · Solving $(x-2)^{x-1}=1$, $(x+2)^{x-2}=1$ and $(2x-1)^{x-3}=1$
Topic 1 · Scalar product of $\mathbf{a}+\mathbf{b}$ and $\mathbf{a}-\mathbf{b}$ using $|\mathbf{a}|^2-|\mathbf{b}|^2$
Topic 4 · Arithmetic mean of a set of measurements
Topic 44 · Distance from the origin to the line $3x+4y+20=0$
Topic 42 · $\cos(a-b)$ from $\sin a$, $\cos b$ at standard angles $30^\circ$, $45^\circ$, $60^\circ$
Topic 42 · Trig ratios table and key identities: applying the reference identities