Foundation June 2017 Paper 1 Q14
14 A number is picked at random from the first four prime numbers.
A number is picked at random from the first four square numbers.
The two numbers are added to get a score.
(a) Complete the table. [4 marks]
| Square numbers | |||||
| + | 1 | 4 | 9 | ||
|---|---|---|---|---|---|
| Prime numbers | 2 | ||||
| 3 | 12 | ||||
| 7 | |||||
(b) What is the probability that the score is a prime number? [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| 16 in top row | B1 | |
| 5 in left column | B1 | |
| All totals correct or All totals correct including for their 16 and their 5 | B2ft | B1ft for seven or more correct totals for the given numbers and their 16 and their 5 (if present) If their 16 is 0, 1, 4 or 9, do not consider those totals If their 5 is 0, 2, 3 or 7, do not consider those totals |
Additional guidance
Fully correct table
| B4 |
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{\text{their correct number of primes}}{\text{their number of completed cells}}\) \(\dfrac{6}{16}\) or \(\dfrac{3}{8}\) if (a) fully correct | B1ft | oe ft their table even if incomplete but must be attempted |
Additional guidance
| Correct decimal and percentage values are 0.375 and 37.5% Do not accept truncated or rounded values unless the correct value has been seen Do not accept ratios or words | ||||||||||||||||||||||||||
Answer \(\dfrac{4}{9}\) | B1ft |