Higher November 2023 Paper 6 Q17
17 Hiro invests £2500 for 2 years in a bank account paying \(r\)% per year compound interest.
At the end of 2 years, the amount in the bank account is £2704.
Calculate \(r\). [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 4 nfww | 4 | M3 for \(\sqrt{\frac{2704}{2500}}\) oe soi by 1.04 or M2 for \(\frac{2704}{2500}\) oe soi by 1.08… or M1 for \(2500x^2 = 2704\) | Condone 4% as final answer for full marks May be done in stages Allow any letter in place of \(x\). Condone use of \(r\) for M1 |
| Alternative method M3 for [\(r =\)] \(100\sqrt{\frac{2704}{2500}} - 100\) or M2 for \(\left[\left(\frac{100 + r}{100}\right)^2 =\right] \frac{2704}{2500}\) or M1 for \(2500 \times \left(\frac{100 + r}{100}\right)^2 = 2704\) oe | May be done in stages Equivalents for \(\frac{100 + r}{100}\) may be seen, eg. \(1 + \frac{r}{100}\) | ||