Higher November 2017 Paper 3 Q9
9 Jack bought a new boat for £12 500
The value, £\(V\), of Jack’s boat at the end of \(n\) years is given by the formula
\(V = 12\,500 \times (0.85)^n\)
(a) At the end of how many years was the value of Jack’s boat first less than 50% of the value of the boat when it was new? (2)
A savings account pays interest at a rate of \(R\)% per year.
Jack invests £5500 in the account for one year.
At the end of the year, Jack pays tax on the interest at a rate of 40%.
After paying tax, he gets £79.20
(b) Work out the value of \(R\). (3)
| Answer | Mark | Notes |
|---|---|---|
| 5 | M1 | evaluates \((0.85)^n\) or \(12\,500 \times (0.85)^n\) for at least one value of \(n\) |
| A1 | cao |
| Answer | Mark | Notes |
|---|---|---|
| 2.4 | P1 | for a process to find the amount of interest before tax, eg \(79.20 \div 0.6\ (= 132)\) |
| P1 | for a process to find value of \(R\), eg \(\text{``}132\text{''} \div 5500 \times 100\) | |
| A1 | cao |