(a)[1]
Write down, in terms of $r$, the probability that Andrei does not cycle to school.
(b(i))[1]
Complete the equation in terms of $r$: $(\,\,\,\,) \times (\,\,\,\,) = 0.4$.
(b(ii))[3]
Show that this equation reduces to $10r^2 - 23r + 9 = 0$.
(b(iii))[3]
Solve $10r^2 - 23r + 9 = 0$ by factorisation.
(b(iv))[1]
Find the chance that Benoit does not cycle to school.