Higher June 2019 Paper 2R Q20
20
\[x = \dfrac{6a}{b - a}\]\(a = 3.46\) correct to 3 significant figures.
\(b = 6.3\) correct to 1 decimal place.
Work out the upper bound for the value of \(x\).
Give your answer as a decimal correct to 3 significant figures.
Show your working clearly.
(3)
| Scheme | Marks |
|---|---|
| 3.455 or 3.465 or 6.25 or 6.35 | M1 |
| \(\dfrac{6 \times 3.465}{6.25 - 3.465}\) | M1 |
| Working required Answer: 7.46 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: Accept \(3.464\dot{9}\) for 3.465 or \(6.34\dot{9}\) for 6.35
M1: \(\dfrac{6 \times \text{UB}_a}{\text{LB}_b - \text{UB}_a}\) where \(3.46 \lt \text{UB}_a \leqslant 3.465\) and \(6.25 \leqslant \text{LB}_b \lt 6.3\)
A1: Dep M2 Accept 7.46499 …