| Exam Board | OCR MEI |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Year | 2009 |
| Session | January |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Indices and Surds |
| Type | Express in form with given base |
| Difficulty | Easy -1.3 This is a straightforward two-part question testing basic index laws and surds. Part (i) requires recognizing 125 = 5³ and √5 = 5^(1/2), then adding exponents. Part (ii) is direct application of power laws. Both are routine recall exercises with minimal problem-solving, significantly easier than average A-level questions. |
| Spec | 1.02a Indices: laws of indices for rational exponents |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(5^{3.5}\) or \(k = 3.5\) or \(7/2\) o.e. | 2 | |
| \(125 = 5^3\) or \(\sqrt{5} = 5^{\frac{1}{2}}\) | M1 | |
| \(5^{\frac{3}{2}}\) o.e. as answer | SC1 | without working |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(16a^6b^{10}\) | 2 | |
| Two 'terms' correct and multiplied | M1 | mark final answer only |
| Total: 4 marks |
# Question 7:
## Part (i):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $5^{3.5}$ or $k = 3.5$ or $7/2$ o.e. | 2 | |
| $125 = 5^3$ or $\sqrt{5} = 5^{\frac{1}{2}}$ | M1 | |
| $5^{\frac{3}{2}}$ o.e. as answer | SC1 | without working |
## Part (ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $16a^6b^{10}$ | 2 | |
| Two 'terms' correct and multiplied | M1 | mark final answer only |
| **Total: 4 marks** | | |
---7 (i) Express $125 \sqrt { 5 }$ in the form $5 ^ { k }$.\\
(ii) Simplify $\left( 4 a ^ { 3 } b ^ { 5 } \right) ^ { 2 }$.
\hfill \mbox{\textit{OCR MEI C1 2009 Q7 [4]}}