Higher June 2025 Paper 1 Q2
2 There are only red counters, white counters, blue counters and green counters in a bag.
Chris is going to take at random a counter from the bag.
The table shows the probability that he will take a red counter and the probability that he will take a white counter.
| Colour | red | white | blue | green |
|---|---|---|---|---|
| Probability | 0.3 | 0.1 |
There are twice as many blue counters as there are green counters in the bag.
(a) Work out the probability that Chris will take a blue counter. (3)
There are 45 red counters in the bag.
(b) Work out the total number of counters in the bag. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| 0.4 | P1 | for \(1 - 0.3 - 0.1\ (= 0.6)\) or \(0.3 + 0.1 + 2x + x = 1\) |
| P1 | for \(\text{``}0.6\text{''} \div 3\ (= 0.2)\) or \(3x = \text{``}0.6\text{''}\) or for \(\text{``}0.6\text{''} \div 3 \times 2\) | |
| A1 | for 0.4 oe |
Additional guidance
Award this mark for any two probabilities that sum to 0.6
Allow P1P1A0 for P(green) = 0.4
Award P1P1A0 for 0.4 with incorrect subsequent working eg \(\dfrac{0.4}{0.6}\)
If no answer on answer line then check table
A0 for \(\dfrac{0.4}{1}\)
| Answer | Mark | Mark scheme |
|---|---|---|
| 150 | M1 | for complete method to find the total number of counters eg \(45 \div 0.3\) or \(45 \div 3 \times 10\) oe or \(45 + 45 \div 3 + 45 \div 3 \times 4 + 45 \div 3 \times 2\ (= 45 + 15 + 60 + 30)\) |
| A1 | cao |
Additional guidance
ft their table