4400 Higher June 2008 Paper 3 Q2
2 A bag contains red discs, black discs and white discs.
The number of black discs is equal to the number of white discs.
Selina is going to take a disc at random from the bag.
The probability that she will take a red disc is 0.6
Work out the probability that she will take a black disc.
(2)
| Scheme | Marks |
|---|---|
| \(\dfrac{1 - 0.6}{2}\) | M1 |
| 0.2 oe | A1 |
| (2) | |
| (2 marks) |
Notes
M1: for 1 − 0.6 or 0.4 seen or \(\frac{x}{2}\) where \(0 \lt x \lt 1\)
A1: for 0.2 oe