Mimi has two bags.
In the first bag there are 3 red balls and 7 green balls.
In the second bag there are 4 red balls and 5 green balls.
Mimi takes at random a ball from the first bag.
She then takes at random a ball from the second bag.
Verify that the probability that Mimi takes two green balls is 718\displaystyle \frac{7}{18}187.
54 exam-style questions on CCEA GCSE Maths Probability Trees. Each one has a worked solution and a mark scheme showing where the marks go.