Higher June 2019 Unit 1 Q13
13.
(a) Express \(0{\cdot}24\dot{8}\) as a fraction. [2]
(b) Evaluate \(\left(\dfrac{1}{27}\right)^{-\frac{2}{3}}\). [2]
| Scheme | Marks | Comments |
|---|---|---|
| \(x\) = 0·2488888..... \(10x\) = 2·488888..... with an attempt to subtract | M1 | Or \(1000x\) and \(100x\), or equivalent. |
| 224/900 or 112/450 or 56/225 or equivalent e.g. 2464/9900 | A1 | An answer of 2·24/9 or 22·4/90 gains M1 only. ISW. |
Alternative method
| Scheme | Marks | Comments |
|---|---|---|
| (0·24 + 0·00888..=) 24/100 + 8/900 or equivalent | M1 | |
| 224/900 (= 56/225) | A1 | ISW |
| Scheme | Marks | Comments |
|---|---|---|
| 9 | B2 | B1 for \(729^{\frac{1}{3}}\) or \(\sqrt[3]{729}\) or \((729/1)^{\frac{1}{3}}\) or \(3^2\) or \((1/9)^{-1}\) or 1/(1/9) Allow B1 for 1/9 or – 9. |