Foundation June 2025 Paper 2 Q21
21 70% of the discs in a box are red and the rest are blue.
- 40% of the red discs are removed.
- 50% of the blue discs are removed.
In total, what percentage of the discs are removed from the box? [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Correct method for 40% of 70% | M1 | eg \(0.4 \times 70\) or 28 or \(0.4 \times 0.7\) or 40% \(\times\) 70% or 0.28 |
| Correct method for 50% of \((100 - 70)\)% | M1 | eg \(0.5 \times 30\) or 15 or \(0.5 \times 0.3\) or 50% \(\times\) 30% or 0.15 0.43 or \(1 - 0.42 - 0.15\) or \(100 - 42 - 15\) implies M2 |
| 43 | A1 | SC2 57 SC1 0.57 |
Additional guidance
| Up to M2 may be awarded for correct work with no answer or incorrect answer, even if this is seen amongst multiple attempts | |
| Do not accept ‘of’ for ‘\(\times\)’ eg 40% of 70% with no further correct method | 1st M0 |
| \(0.4 \times 0.7\) and \(0.5 \times (1 - 0.7)\) may be seen embedded eg1 (200 discs) \(0.4 \times 0.7 \times 200\) \(0.5 \times 0.3 \times 200\) eg2 (\(d\) discs) \(0.4 \times 0.7 \times d\) \(0.5 \times 0.3 \times d\) | M1 M1 M1 M1 |
| SC2 is for working out the percentage of discs that are not removed |