Higher January 2021 Paper 1R Q19
19 \(k = \dfrac{t}{a - h}\)
\(t = 14\) correct to 2 significant figures
\(a = 7.8\) correct to 2 significant figures
\(h = 3.4\) correct to 2 significant figures
Work out the lower bound for the value of \(k\).
Show your working clearly.
(3)
| Scheme | Marks |
|---|---|
| 7.75, 7.85, 3.35, 3.45, 13.5, 14.5 | B1 |
| \((k =)\; \dfrac{13.5}{7.85 - 3.35}\) | M1 |
| Correct answer scores full marks (unless from obvious incorrect working) Answer: 3 | A1 |
| (3) | |
| (3 marks) |
Notes
B1: for sight of a correct upper or lower bound
Accept
\(3.44\dot{9}\) for 3.45 or
\(7.84\dot{9}\) for 7.85 or
\(14.4\dot{9}\) for 14.5
M1: for correct substitution into \(k = \dfrac{t_{LB}}{a_{UB} - h_{LB}}\)
where \(13.5 \leqslant t_{LB} \lt 14\) and \(7.8 \lt a_{UB} \leqslant 7.85\) and \(3.35 \leqslant h_{LB} \lt 3.4\)
A1: accept 3.0