| Exam Board | WJEC |
|---|---|
| Module | Unit 1 (Unit 1) |
| Year | 2019 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Binomial Theorem (positive integer n) |
| Type | Standard binomial expansion coefficient |
| Difficulty | Moderate -0.3 This is a straightforward binomial expansion question testing standard formula application. Parts (a) and (b) are routine recall (n+1 terms, using nCr formula), while part (c) requires finding when coefficients change sign and comparing magnitudes—slightly more thought than pure recall but still a standard textbook exercise with no novel problem-solving required. |
| Spec | 1.04a Binomial expansion: (a+b)^n for positive integer n |
In the binomial expansion of $(2 - 5x)^8$, find
\begin{enumerate}[label=(\alph*)]
\item the number of terms, [1]
\item the $4^{\text{th}}$ term, when the expansion is in ascending powers of $x$, [2]
\item the greatest positive coefficient. [3]
\end{enumerate}
\hfill \mbox{\textit{WJEC Unit 1 2019 Q12 [6]}}