4400 Higher November 2009 Paper 4 Q4
4 A bag contains some beads.
The colour of each bead is red or green or blue.
Binita is going to take a bead at random from the bag.
The probability that she will take a red bead is 0.4
The probability that she will take a green bead is 0.5
(a) Work out the probability that she will take a blue bead. (2)
(b) There are 80 beads in the bag.
Work out the number of red beads in the bag. (2)
Work out the number of red beads in the bag. (2)
| Scheme | Marks |
|---|---|
| 1 − (0.4 + 0.5) | M1 |
| 0.1 | A1 |
| (2) |
Notes
A1: Also accept \(\frac{0.1}{1}\)
| Scheme | Marks |
|---|---|
| 0.4 × 80 or \(\dfrac{n}{80} = 0.4\) | M1 |
| 32 | A1 |
| (2) | |
| (4 marks) |
Notes
A1: cao