Higher June 2019 Paper 6 Q10
10 In 2017, the value of a house increased by 4%.
In 2018, the value of the house then decreased by 3%.
Teresa says
Over the two years the value of the house increased by exactly 1% because 4 – 3 = 1.
Show that Teresa is wrong. [6]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| [0].88% [increase] | 6 | B5 for 1.0088 or [0].0088 seen or B4 for \(1.0088x\) where \(x\) is any letter or M4 for \(k\) × 1.04 × [0].97 ÷ \(k\) oe or (\(k\) × 1.04 × [0].97 – \(k\)) ÷ \(k\) oe or M3 for \(k\) × 1.04 × [0].97 oe or M2 for \(k\) × 1.04 oe or \(k\) × [0].97 oe or M1 for 1.04 or [0].97 or 4% of \(k\) found or 3% of \(k\) found If 0 scored then SC3 for figs 10088 or 88 seen | Accept [0].9% increase after 1.0088 found For M marks, \(k\) is any seen starting value or a letter. e.g. M4 for 1.04 × [0].97 as \(k\) assumed to be 1. e.g. M3 for 104 × [0].97 as \(k\) assumed to be 100. M2 or M1 may be embedded in an incorrect calculation, or in stages e.g. M2 for \(k\) × 1.4 × [0].97 e.g. M1 for \(k\) × 1.4 × [0].03 |
| Alternative method The two answers are different oe dep on B5 | B5 for correct answers to both \(k\) × 1.04 × [0].97 and \(k\) × 1.01 OR M3 for \(k\) × 1.04 × [0].97 oe or M2 for \(k\) × 1.04 oe or \(k\) × [0].97 oe or M1 for 1.04 or [0].97 or 4% of \(k\) found or 3% of \(k\) found and M1 for \(k\) × 1.01 oe | Alternative method Answers to these calculations must be checked | |