OCR MEI C1 2013 June — Question 7 5 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2013
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeExpress in form with given base
DifficultyModerate -0.8 Part (i) is straightforward index manipulation (125 = 5³, so answer is 5^3.5). Part (ii) requires rationalizing the denominator by multiplying by the conjugate, then collecting terms - a standard C1 technique but with slightly more algebraic manipulation than the most basic questions. Overall easier than average A-level questions due to being pure procedural recall with no problem-solving or novel insight required.
Spec1.02a Indices: laws of indices for rational exponents1.02b Surds: manipulation and rationalising denominators

  1. Express \(125\sqrt{5}\) in the form \(5^t\). [2]
  2. Simplify \(10 + 7\sqrt{5} + \frac{38}{1 - 2\sqrt{5}}\), giving your answer in the form \(a + b\sqrt{5}\). [3]

\begin{enumerate}[label=(\roman*)]
\item Express $125\sqrt{5}$ in the form $5^t$. [2]
\item Simplify $10 + 7\sqrt{5} + \frac{38}{1 - 2\sqrt{5}}$, giving your answer in the form $a + b\sqrt{5}$. [3]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C1 2013 Q7 [5]}}