Foundation November 2019 Paper 1 Q11
11 In a raffle, 200 tickets are sold.
The tickets are either red or blue.
The winning ticket is picked at random.
(a) What is the probability that the winning ticket is green? [1 mark]
(b) 79 children and 90 women buy one ticket each.
Men buy the rest of the tickets.
Work out the probability that a man buys the winning ticket. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| 0 | B1 | oe fraction, decimal or percentage |
Additional guidance
| zero or nought | B1 |
| 0% | B1 |
| \(\dfrac{0}{n}\); \(n\) is an integer > 0, eg \(\dfrac{0}{200}\) | B1 |
| With B1 scored, ignore probability words unless contradictory eg 0, impossible eg 0, unlikely | B1 B0 |
| Zero chance | B0 |
| Nothing or nil | B0 |
| 0 out of 200 | B0 |
| 0 in 200 | B0 |
| No | B0 |
| No chance | B0 |
| Impossible | B0 |
| Not possible | B0 |
| Any of the B0 responses above, with a B1 answer | B1 |
| 0 : 200 or 0 to 200 (even with B1 response, still scores B0) | B0 |
| Answer | Mark | Comments |
|---|---|---|
| \(200 - 79 - 90\) or 31 or \(\dfrac{79}{200} + \dfrac{90}{200}\) or \(1 - \left(\dfrac{79}{200} + \dfrac{90}{200}\right)\) or \(\dfrac{(200 - 79 - 90)}{200}\) or \(\dfrac{169}{200}\) | M1 | oe eg \(200 - (79 + 90)\) eg 0.395 + 0.45 or 0.845 |
| \(\dfrac{31}{200}\) or 0.155 or 15.5% | A1 | accept 0.16 or 16% if no errors seen |
Additional guidance
| Ignore incorrect cancelling or incorrect conversion to a decimal or a percentage or incorrect rounding after correct answer seen | |
| eg \(\dfrac{31}{200}\) seen, then answer \(\dfrac{3}{20}\) | M1A1 |
| eg 15.5% seen, then answer 15% | M1A1 |
| Answer 0.16 or 16% with M1 work not seen | M1A1 |
| 31 : 200 or 31 : 169 or 31 out of 200 or 31 in 200 | M1A0 |
| Ignore probability words unless contradictory eg \(\dfrac{31}{200}\) unlikely eg \(\dfrac{31}{200}\) likely | M1A1 M1A0 |