Foundation November 2018 Paper 1 Q27
27 Amina has two bags.
In the first bag there are 3 red balls and 7 green balls.
In the second bag there are 5 red balls and 4 green balls.
Amina takes at random a ball from the first bag.
She then takes at random a ball from the second bag.
(a) Complete the probability tree diagram.
(b) Work out the probability that Amina takes two red balls. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(\dfrac{7}{10}, \dfrac{4}{9}, \dfrac{5}{9}, \dfrac{4}{9}\) | B2 | for all probabilities correct (oe) |
| (B1 | for 2 or 3 correct) |
| Answer | Mark | Mark scheme |
|---|---|---|
| \(\dfrac{15}{90}\) | M1 | for \(\dfrac{3}{10} \times \dfrac{5}{9}\) oe |
| A1 | \(\dfrac{15}{90}\) oe |
Additional guidance
Accept any equivalent fraction, decimal form 0.16(6...) or 0.17 or percentage form 16(.6...)% or 17%