Higher November 2020 Paper 2 Q13
13 Use algebra to show that \(0.6\dot{8}\dot{1} = \dfrac{15}{22}\)
(2)
| Scheme | Marks |
|---|---|
| e.g. \(x = 0.6\dot{8}\dot{1}\) and \(100x = 68.\dot{1}\dot{8}\) or \(10x = 6.\dot{8}\dot{1}\) and \(1000x = 681.\dot{8}\dot{1}\) | M1 |
\(99x = 67.5\), \(x = \dfrac{67.5}{99} = \dfrac{15}{22}\) or \(990x = 675\), \(x = \dfrac{675}{990} = \dfrac{15}{22}\) oe Working required Answer: show | A1 |
| (2) | |
| (2 marks) |
Notes
M1: e.g. two decimals that when subtracted give a finite decimal (must show understanding of recurring figures by ‘dot’ or at least 2 lots of 18 or 81 after the decimal point). Algebra required, use of any letter.
A1: dep for completing the ‘show that’ arriving at given answer from correct working.