Foundation June 2018 Unit 2 Q20
20. A box contains many discs, identical in shape and size.
A picture of one of four Welsh castles is printed on each disc.
(a) A disc is chosen at random from the box.
Complete the table below to find the probability of choosing a disc showing Dinefwr Castle. [2]
Complete the table below to find the probability of choosing a disc showing Dinefwr Castle. [2]
| Picture | Caernarfon Castle | Harlech Castle | Rhuddlan Castle | Dinefwr Castle |
|---|---|---|---|---|
| Probability | 0·36 | 0·12 | 0·24 |
(b) In the box, there were 522 discs showing a picture of Caernarfon Castle.
How many of the discs showed a picture of Harlech Castle? [2]
How many of the discs showed a picture of Harlech Castle? [2]
| Scheme | Marks | Comments |
|---|---|---|
| 1 − 0·36 − 0·12 − 0·24 | M1 | |
| = 0·28 | A1 |
| Scheme | Marks | Comments |
|---|---|---|
| 522 × ⅓ or equivalent (e.g. 522 ÷ 0·36 × 0·12) | M1 | |
| = 174 | A1 |