Foundation June 2023 Paper 2 Q11
11 Here is a Venn diagram.
\(\xi\) = 60 people
H = people who own a gaming headset
W = people who own a smart watch

(a) 15 of the people own a smart watch.
Complete the Venn diagram. [2 marks]
(b) One of the 60 people is chosen at random.
What is the probability that they own both a gaming headset and a smart watch? [1 mark]
(c) Marek is going to buy a gaming headset that costs £35
He already has £19
He plans to save the rest in two equal amounts over the next two weeks.
He uses this method to work out in pounds how much to save each week.
| \(35 - 19 \div 2\) |
What is wrong with his method? [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| 8 in W only | B1 | |
| 21 in (H U W)' | B1ft | ft \(29 -\) their 8 their 8 must be \(\lt 29\) |
Additional guidance
| 15 in W only 21 in (H U W)' | B0 B1 |
| 15 in W only 14 in (H U W)' | B0 B1ft |
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{7}{60}\) or [0.116, 0.117] or [11.6, 11.7]% | B1 | oe fraction |
Additional guidance
Ignore conversion attempt to decimal, fraction or percentage (but not ratio) after correct probability seen
Do not allow eg 7 in 60 or 7 out of 60 unless the correct probability seen
Do not allow ratio
Ignore words if correct probability seen
| Answer | Mark | Comments |
|---|---|---|
| Valid explanation | B1 | eg needs brackets around \(35 - 19\) |
Additional guidance
| Any calculations shown must be correct | |
| Ignore irrelevant, non-contradictory statements | |
| It gives 25.5 and it should be 8 | B1 |
| (It gives the wrong answer,) it should be 8 | B1 |
| He shouldn’t divide (by 2) first | B1 |
| He needs brackets around the takeaway | B1 |
| He needs to subtract first | B1 |
| He should do \(35 - 19\) and then divide by 2 | B1 |
| \((35 - 19) \div 2\) (may correct the given calculation by adding brackets) | B1 |
| \(\dfrac{35 - 19}{2}\) (implies the brackets) | B1 |
| This gives 25.5 (or 51) when he needs 8 or 16 | B1 |
| \(35 - 19 = 16 \quad 16 \div 2 = 8\) (needs to say that this is what he should do) | B0 |
| This gives 25.5 (or 51) which is too much (needs to compare with 8 or 16) | B0 |
| He hasn’t used BIDMAS | B0 |
| It gives the wrong answer | B0 |
| \(35 - 19 \div 2 = 8\) | B0 |
| \(35 - 19 \div 2 = 25.50\) | B0 |
| He needs brackets | B0 |