Foundation November 2021 Paper 3 Q26
26 In a bag there are only red counters, blue counters, green counters and pink counters.
A counter is going to be taken at random from the bag.
The table shows the probabilities of taking a red counter or a blue counter.
| Colour | red | blue | green | pink |
|---|---|---|---|---|
| Probability | 0.05 | 0.15 |
The probability of taking a green counter is 0.2 more than the probability of taking a pink counter.
(a) Complete the table. (2)
There are 18 blue counters in the bag.
(b) Work out the total number of counters in the bag. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| 0.5, 0.3 | P1 | for \(1 - 0.05 - 0.15\ (= 0.8)\) |
| A1 | oe |
Additional guidance
Award this mark for any two probabilities that sum to 0.8
| Answer | Mark | Mark scheme |
|---|---|---|
| 120 | M1 | \(18 \div 0.15\) oe or \(6 + 18 + a + b\) where \(a + b = 96\) |
| A1 | cao |