In a laboratory experiment, the concentration QQQ (in mol/L) of a chemical reagent over a specific time interval t t\,t is modelled by the function Q(t)=(43−6t)9\displaystyle Q(t) = \left(\frac{4}{3} - 6t\right)^9Q(t)=(34−6t)9. Determine the exact value of the coefficient of the term in t4 t^4\,t4 in the binomial expansion of Q(t)Q(t)Q(t), giving your answer as an integer in simplest form.
308 exam-style questions on OCR A Level Maths 1.4 Sequences and Series, covering 1.4.1 Binomial expansion for positive integer n, 1.4.2 Link to binomial probabilities, 1.4.3 Binomial expansion for rational n (A-level only), 1.4.4 Validity of the expansion (A-level only), 1.4.5 Sequences (A-level only), 1.4.6 Increasing, decreasing and periodic sequences (A-level only), 1.4.7 Sigma notation (A-level only), 1.4.8 Arithmetic sequences and series (A-level only), 1.4.9 Geometric sequences and series (A-level only), 1.4.10 Sum to infinity of a geometric series (A-level only), and 1.4.11 Modelling with sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.