| Exam Board | Pre-U |
|---|---|
| Module | Pre-U 9794/1 (Pre-U Mathematics Paper 1) |
| Year | 2013 |
| Session | June |
| Marks | 4 |
| Topic | Binomial Theorem (positive integer n) |
| Type | Standard binomial expansion coefficient |
| Difficulty | Easy -1.2 This is a straightforward application of the binomial theorem requiring only substitution into the formula C(5,3)×1²×(-2x)³. It's a single-step calculation with no problem-solving required, making it easier than average but not trivial since students must correctly handle the negative sign and power. |
| Spec | 1.04a Binomial expansion: (a+b)^n for positive integer n |
State 10 — B1
State $(-2)^3$ — B1
Attempt product of binomial coefficient and power of 2 — M1
Obtain $-80$ — A1 **[4]**
Or
Attempted expansion of 3 brackets — [M1
Obtain $-32x^3 - 48x^3$ — A1
Obtain $-80$ — A1] **[4]**2 Find the coefficient of $x ^ { 3 }$ in the expansion of $( 1 - 2 x ) ^ { 5 }$.
\hfill \mbox{\textit{Pre-U Pre-U 9794/1 2013 Q2 [4]}}