Higher November 2017 Paper 2 Q4
4. The score from the two spinners shown is 2 + 5 = 7.
The score is the sum of the two outcomes.
(a) What is the lowest possible score? [1]
(b) Is it possible to get a score \(\geqslant 9\)?
Give a reason for your answer. [1]
Give a reason for your answer. [1]
Yes ☐ No ☐
(c) Ryan says,
You can score 5 with these spinners by getting 1 + 4 or 2 + 3,
so the probability of scoring 5 is \(\dfrac{2}{\text{the number of possible outcomes}}\)
- Comment on Ryan’s method.
- Find the probability of scoring 5.
| Scheme | Marks | Comments |
|---|---|---|
| 2 | B1 |
| Scheme | Marks | Comments |
|---|---|---|
| ‘Yes’ selected or unambiguously implied AND a reason, e.g. ‘Yes, 4 + 5’, ‘Yes it is possible to score 9’ | B1 | Ignore further irrelevant statements |
| Scheme | Marks | Comments |
|---|---|---|
| States or implies that the list to score 5 is incomplete, e.g. ‘Ryan has missed 4+1 and 3+2’ | M1 | |
| States or implies that \(\dfrac{\text{number of ways of scoring 5}}{\text{the number of outcomes}}\) is a correct method | M1 | Accept sight of \(\dfrac{4}{\text{‘their number of outcomes’}}\), provided ‘their number of outcomes’ > 10, or sight of 1/5 |
| 4/20 (= 1/5) | A1 | ISW. Depends on M1, M1 previously awarded If no marks, allow SC1 for an answer of 2/20 or equivalent |
| (5) |
Corrected by Westie's Workshop
- The board's mark scheme printed “‘their number of outcomes > 10”. Changed to “‘their number of outcomes’ > 10” because a closing quotation mark was missing after “their number of outcomes”.
- The board's mark scheme printed “‘Ryan has missed 4+1 and 3+2”. Changed to “‘Ryan has missed 4+1 and 3+2’” because a closing quotation mark was missing.
Original: see the board's mark scheme PDF (link above).