Easy -1.8 This is a fragment asking students to repeat two lines of a bubble sort algorithm until a stopping condition. It requires only basic understanding of algorithm notation and iteration—purely procedural recall with no problem-solving, calculation, or proof involved. Significantly easier than typical A-level questions.
Forward pass (must have at least one join correct)
M1
forward pass
Forward pass answer correct (FT)
A1
FT
Backward pass (must have at least one burst correct)
M1
backward pass
Backward pass answer correct (FT)
A1
FT
Minimum completion time = 100 minutes
B1
cao
Critical activities: A, C, D, I, J and L
B1
cao
[6]
Part (iii)
Answer
Marks
Guidance
Answer
Marks
Guidance
e.g. Critical activities (100 mins) + others; e.g. B has to be done whilst A is underway
B1
Needs a comparison of times, possibly implied
[1]
Part (iv)
Answer
Marks
Guidance
Answer
Marks
Guidance
Cascade diagram with Simon and Friend, no more than 1 activity omitted
M1
diagram like this or attempted cascade; no more than 1 activity omitted
Nowhere needing more than 2 people
A1
nowhere needing more than 2 people
Precedences correct
A1
precedences correct
Fully correct, including who does what
A1
fully correct, inc who does what
[4]
## Question 4:
### Parts (i) & (ii)
| Answer | Marks | Guidance |
|--------|-------|----------|
| Activity on arc | M1 | activity on arc |
| Single start and end | A1 | single start and end |
| A, B, C OK | A1 | A, B, C OK |
| D, F, I OK | A1 | D, F, I OK |
| rest OK | A1 | rest OK |
| | **[5]** | |
| Forward pass (must have at least one join correct) | M1 | forward pass |
| Forward pass answer correct (FT) | A1 | FT |
| Backward pass (must have at least one burst correct) | M1 | backward pass |
| Backward pass answer correct (FT) | A1 | FT |
| Minimum completion time = 100 minutes | B1 | cao |
| Critical activities: A, C, D, I, J and L | B1 | cao |
| | **[6]** | |
### Part (iii)
| Answer | Marks | Guidance |
|--------|-------|----------|
| e.g. Critical activities (100 mins) + others; e.g. B has to be done whilst A is underway | B1 | Needs a comparison of times, possibly implied |
| | **[1]** | |
### Part (iv)
| Answer | Marks | Guidance |
|--------|-------|----------|
| Cascade diagram with Simon and Friend, no more than 1 activity omitted | M1 | diagram like this or attempted cascade; no more than 1 activity omitted |
| Nowhere needing more than 2 people | A1 | nowhere needing more than 2 people |
| Precedences correct | A1 | precedences correct |
| Fully correct, including who does what | A1 | fully correct, inc who does what |
| | **[4]** | |
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