4MA0 Higher January 2017 Paper 3 Q20
20 \(x = 3\qquad\) correct to 1 significant figure.
\(y = 8.37\quad\) correct to 3 significant figures.
\(z = 5.3\qquad\) correct to 1 decimal place.
Calculate the upper bound of \(\;x(y - z)\)
Show your working clearly.
(3)
| Scheme | Marks |
|---|---|
| 3.5 or 2.5 or 5.25 or 5.35 or 8.365 or 8.375 | M1 |
| 3.5(8.375 – 5.25) or 3.5 × 8.375 – 3.5 × 5.25 | M1 |
| \(\dfrac{175}{16}\) or 10.9375 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: accept \(3.4\dot{9}\) or 3.499… or \(5.34\dot{9}\) or 5.3499... or \(8.374\dot{9}\) or 8.37499..
M1: or for \(\mathrm{UB}_1 \times (\mathrm{UB}_2 - \mathrm{LB})\) oe where
\(3 \lt \mathrm{UB}_1 \leqslant 3.5\) and \(8.37 \lt \mathrm{UB}_2 \leqslant 8.375\) and \(5.25 \leqslant \mathrm{LB} \lt 5.3\)
A1: dep on M2 – correct working must be seen