4MA0 Foundation June 2015 Paper 2 Q14
14
(a) Write down the probability of an event that is impossible. (1)
The probability that Jamil will be late for work is 0.2
(b) Work out the probability that Jamil will not be late for work. (1)
A bag contains only red bricks and blue bricks.
There is a total of 20 bricks in the bag.
The probability that a brick taken at random from the bag will be red is \(\dfrac{2}{5}\)
(c) How many blue bricks are there in the bag? (3)
| Scheme | Marks |
|---|---|
| 0 | B1 |
| (1) |
Notes
B1: 0%
| Scheme | Marks |
|---|---|
| 0.8 oe | B1 |
| (1) |
| Scheme | Marks |
|---|---|
| \(1 - \dfrac{2}{5}\) or \(\dfrac{3}{5}\) oe | M1 |
| \(\dfrac{3}{5} \times 20\) oe | M1 |
| 12 | A1 |
| (3) | |
| Total 5 marks |
Notes
M1: or for \(\dfrac{2}{5} \times 20\) oe or 8 or \(\dfrac{8}{20}\)
M1: (dep) for 20 − ‘8’
A1: (NB: \(\dfrac{12}{20}\) gains M2, A0)