1MA0 Higher November 2012 Paper 1 Q8
8 There are only red counters, blue counters, white counters and black counters in a bag.
The table shows the probability that a counter taken at random from the bag will be red or blue.
| Colour | red | blue | white | black |
|---|---|---|---|---|
| Probability | 0.2 | 0.5 |
The number of white counters in the bag is the same as the number of black counters in the bag.
Tania takes at random a counter from the bag.
(a) Work out the probability that Tania takes a white counter. (2)
There are 240 counters in the bag.
(b) Work out the number of red counters in the bag. (2)
| Answer | Mark | Notes |
|---|---|---|
| 0.15 | 2 | M1 for 1 – (0.2 + 0.5) oe or sight of 0.3 A1 oe |
| Answer | Mark | Notes |
|---|---|---|
| 48 | 2 | M1 for 240 × 0.2 oe or 48 + 120 + 36 +36 A1 cao |