Foundation November 2017 Paper 1 Q13
13 A bus can be early, on time or late.
The probability that the bus is early is 0.1
The probability that the bus is on time is 0.6
Work out the probability that the bus is late. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(1 - 0.1 - 0.6\) or \(1 - (0.1 + 0.6)\) or \(1 - 0.7\) | M1 | oe |
| 0.3 | A1 | oe eg 30% or \(\dfrac{3}{10}\) |
Additional guidance
| \(1 - 0.1 + 0.6 = 0.3\) (recovered) \(1 - 0.1 + 0.6 = 1.5\) (not recovered) \(0.6 \div 2 = 0.3\) (incorrect method) | M1A1 M0A0 M0A0 |
| Embedded, correct answer, eg \(0.3 + 0.1 + 0.6 = 1\) | M1A0 |
| \(\dfrac{0.3}{1}\) unless 0.3 already seen | M1A0 |