Higher June 2019 Paper 2 Q17
17
\[m = \frac{p - 2b}{2}\]\(p = 68.3 \qquad\) correct to 1 decimal place.
\(b = 8.7 \qquad\) correct to 1 decimal place.
Work out the lower bound for \(m\). [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| 68.3 – 0.05 or 68.25 or 68.3 + 0.05 or 68.35 or 8.7 – 0.05 or 8.65 or 8.7 + 0.05 or 8.75 | M1 | accept \(68.34\dot{9}\) for 68.35 accept \(8.74\dot{9}\) for 8.75 may be seen in an inequality eg \(68.25 \leqslant p < 68.35\) |
| \(\dfrac{[68.2, 68.3) - 2 \times (8.7, 8.8]}{2}\) | M1 | oe \(\dfrac{68.25 - 2 \times 8.75}{2}\) or \(\dfrac{68.25 - 17.5}{2}\) or \(\dfrac{50.75}{2}\) is M2 |
| 25.375 or \(\dfrac{203}{8}\) or \(25\dfrac{3}{8}\) | A1 | SC2 Answer 25.375 and 25.525 |
Additional guidance
| 1st M1 If given as an inequality condone incorrect notation eg \(68.25 \leqslant p \leqslant 68.35\) | M1 |
| Ignore any subsequent rounding after 25.375 seen | |
| Condone eg 68.250 for 68.25 | M1 |
| Answer 25.3 or 25.4 with no correct working | M0M0A0 |
| Only working for upper bound eg \(\dfrac{68.35 - 2 \times 8.65}{2} = 25.525\) | M1M0A0 |