Foundation June 2018 Paper 1 Q16
16 Finn has two bags of counters.
He takes a counter at random from each bag.
The probability that he takes a red counter from the first bag is 0.3.
The probability that he takes a red counter from the second bag is 0.4.
What is the probability that he takes at least one red counter? [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 0.58 oe | 4 | M3 for 0.3 \(\times\) 0.4 + 0.3 \(\times\) 0.6 + 0.7 \(\times\) 0.4 or 1 – (0.7 \(\times\) 0.6) Or M2 for two correct products or 0.42 Or M1 for one correct product Or B1 for 0.7 and 0.6 seen (may be on a tree diagram oe) | implied by 0.12 + 0.18 + 0.28 allow equivalent fractions 0.42 cannot be one of the 2 products as it’s a different method |